xenial (1) rasmol-classic.1.gz

Provided by: rasmol_2.7.5.2-2_amd64 bug

NAME

       rasmol - Molecular Graphics Visualisation Tool v2.7.5

SYNOPSIS

       rasmol [-nodiplay] [[-format ] filename] [-script scriptfile]

FORMATS

       -pdb        Protein Data Bank
       -mdl        MDL's MOL File Format
       -mol2       Tripos' Sybyl MOL2 Format
       -xyz        MSC's XYZ (XMol) Format
       -mopac      MOPAC Input or Output File Format
       -alchemy    Alchemy File Format
       -charmm     CHARMm File Format
       -cif        IUCr CIF or CIF File Format

NOTICES

       This  software has been created from several sources.  Much of the code is from RasMol 2.6, as created by
       Roger Sayle.  The torsion angle  code,  new  POVRAY3  code  and  other  features  are  derived  from  the
       RasMol2.6x1  revisions  by  Arne  Mueller.   The  Ramachandran  printer plot code was derived from fisipl
       created by Frances C.  Bernstein.  See the Protein Data Bank program tape.

       The code to display multiple molecules and to allow bond rotation is derived in large part from  the  UCB
       mods  by  Gary  Grossman  and Marco Molinaro, included with permission of Eileen Lewis of the ModularCHEM
       Consortium.

       The CIF modifications make use of a library based in part on CBFlib by  Paul  J.  Ellis  and  Herbert  J.
       Bernstein.   Parts  of  CBFlib  is loosely based on the CIFPARSE software package from the NDB at Rutgers
       university.  Please type the RasMol commands help copying, help general, help IUCR, help CBFlib,
        and help CIFPARSE for applicable notices.  Please type help copyright for copyright notices.  If you use
       RasMol V2.6 or an earlier version, type the RasMol command help oldnotice.

COPYING

       This  version  is  based  directly on RasMol version 2.7.4.2, on RasMol verion 2.7.4.2, on RasMol version
       2.7.4, on RasMol version 2.7.3.1, on RasMol version 2.7.3, on RasMol version  2.7.2.1.1,  Rasmol  version
       2.7.2,  RasMol  version  2.7.1.1  and RasTop version 1.3 and indirectly on the RasMol 2.5-ucb and 2.6-ucb
       versions and version 2.6_CIF.2, RasMol 2.6x1 and RasMol_2.6.4.

       RasMol 2.7.5 may be distributed under the terms of the GNU General Public License (the GPL), see

                 http://www.gnu.org/licenses/gpl.txt

       or the file GPL or type the command help GPL

       or RasMol 2.7.5 may be distributed under the RASMOL license.  See the file NOTICE  or  type  the  command
       help RASLIC

       GPL
                                  GNU GENERAL PUBLIC LICENSE
                                     Version 2, June 1991

               Copyright (C) 1989, 1991 Free Software Foundation, Inc.
                                     59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
               Everyone is permitted to copy and distribute verbatim copies
               of this license document, but changing it is not allowed.

                                          Preamble

                The  licenses  for  most software are designed to take away your freedom to share and change it.
              By contrast, the GNU General Public License is intended to guarantee your  freedom  to  share  and
              change  free  software--to  make sure the software is free for all its users.  This General Public
              License applies to most of the Free Software Foundation's software and to any other program  whose
              authors  commit  to using it.  (Some other Free Software Foundation software is covered by the GNU
              Library General Public License instead.)  You can apply it to your programs, too.

                When we speak of free software, we are referring to freedom,  not  price.   Our  General  Public
              Licenses are designed to make sure that you have the freedom to distribute copies of free software
              (and charge for this service if you wish), that you receive source code or can get it if you  want
              it,  that  you can change the software or use pieces of it in new free programs; and that you know
              you can do these things.

                To protect your rights, we need to make restrictions that forbid anyone to deny you these rights
              or  to  ask you to surrender the rights.  These restrictions translate to certain responsibilities
              for you if you distribute copies of the software, or if you modify it.

                For example, if you distribute copies of such a program, whether gratis or for a fee,  you  must
              give  the  recipients all the rights that you have.  You must make sure that they, too, receive or
              can get the source code.  And you must show them these terms so they know their rights.

                We protect your rights with two steps: (1) copyright  the  software,  and  (2)  offer  you  this
              license which gives you legal permission to copy, distribute and/or modify the software.

                Also,  for  each author's protection and ours, we want to make certain that everyone understands
              that there is no warranty for this free software.  If the software is modified by someone else and
              passed  on,  we  want  its recipients to know that what they have is not the original, so that any
              problems introduced by others will not reflect on the original authors' reputations.

                Finally, any free program is threatened constantly by software patents.  We wish  to  avoid  the
              danger  that  redistributors of a free program will individually obtain patent licenses, in effect
              making the program proprietary.  To prevent this, we have made it clear that any  patent  must  be
              licensed for everyone's free use or not licensed at all.

                The precise terms and conditions for copying, distribution and modification follow.

                                  GNU GENERAL PUBLIC LICENSE
                 TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION

                0.  This  License  applies  to  any  program or other work which contains a notice placed by the
              copyright holder saying it may be distributed under the terms of this General Public License.  The
              "Program",  below,  refers  to  any  such program or work, and a "work based on the Program" means
              either the Program or any derivative work under copyright law: that is to say, a  work  containing
              the  Program  or  a  portion  of  it, either verbatim or with modifications and/or translated into
              another  language.   (Hereinafter,  translation  is  included  without  limitation  in  the   term
              "modification".)  Each licensee is addressed as "you".

              Activities other than copying, distribution and modification are not covered by this License; they
              are outside its scope.  The act of running the Program is not restricted, and the output from  the
              Program  is  covered  only  if its contents constitute a work based on the Program (independent of
              having been made by running the Program).  Whether that is true depends on what the Program does.

                1. You may copy and distribute verbatim copies of the Program's source code as you  receive  it,
              in  any  medium,  provided  that  you  conspicuously  and  appropriately  publish  on each copy an
              appropriate copyright notice and disclaimer of warranty; keep intact all the notices that refer to
              this  License  and  to the absence of any warranty; and give any other recipients of the Program a
              copy of this License along with the Program.

              You may charge a fee for the physical act of transferring a copy, and you may at your option offer
              warranty protection in exchange for a fee.

                2.  You  may modify your copy or copies of the Program or any portion of it, thus forming a work
              based on the Program, and copy and distribute such  modifications  or  work  under  the  terms  of
              Section 1 above, provided that you also meet all of these conditions:

                  a) You must cause the modified files to carry prominent notices
                  stating that you changed the files and the date of any change.

                  b) You must cause any work that you distribute or publish, that in
                  whole or in part contains or is derived from the Program or any
                  part thereof, to be licensed as a whole at no charge to all third
                  parties under the terms of this License.

                  c) If the modified program normally reads commands interactively
                  when run, you must cause it, when started running for such
                  interactive use in the most ordinary way, to print or display an
                  announcement including an appropriate copyright notice and a
                  notice that there is no warranty (or else, saying that you provide
                  a warranty) and that users may redistribute the program under
                  these conditions, and telling the user how to view a copy of this
                  License.  (Exception: if the Program itself is interactive but
                  does not normally print such an announcement, your work based on
                  the Program is not required to print an announcement.)

              These  requirements  apply to the modified work as a whole.  If identifiable sections of that work
              are not derived from the Program, and can be reasonably considered independent and separate  works
              in  themselves,  then  this  License,  and  its  terms,  do  not  apply to those sections when you
              distribute them as separate works.  But when you distribute the same sections as part of  a  whole
              which  is  a work based on the Program, the distribution of the whole must be on the terms of this
              License, whose permissions for other licensees extend to the entire whole, and thus  to  each  and
              every part regardless of who wrote it.

              Thus,  it is not the intent of this section to claim rights or contest your rights to work written
              entirely by you; rather, the intent is to exercise  the  right  to  control  the  distribution  of
              derivative or collective works based on the Program.

              In addition, mere aggregation of another work not based on the Program with the Program (or with a
              work based on the Program) on a volume of a storage or distribution  medium  does  not  bring  the
              other work under the scope of this License.

                3.  You  may  copy and distribute the Program (or a work based on it, under Section 2) in object
              code or executable form under the terms of Sections 1 and 2 above provided that you also do one of
              the following:

                  a) Accompany it with the complete corresponding machine-readable
                  source code, which must be distributed under the terms of Sections
                  1 and 2 above on a medium customarily used for software interchange; or,

                  b) Accompany it with a written offer, valid for at least three
                  years, to give any third party, for a charge no more than your
                  cost of physically performing source distribution, a complete
                  machine-readable copy of the corresponding source code, to be
                  distributed under the terms of Sections 1 and 2 above on a medium
                  customarily used for software interchange; or,

                  c) Accompany it with the information you received as to the offer
                  to distribute corresponding source code.  (This alternative is
                  allowed only for noncommercial distribution and only if you
                  received the program in object code or executable form with such
                  an offer, in accord with Subsection b above.)

              The  source  code  for a work means the preferred form of the work for making modifications to it.
              For an executable work, complete source code  means  all  the  source  code  for  all  modules  it
              contains,  plus  any  associated  interface  definition  files,  plus  the scripts used to control
              compilation and installation of the executable.  However, as a special exception, the source  code
              distributed  need  not  include  anything that is normally distributed (in either source or binary
              form) with the major components (compiler, kernel, and so on) of the operating system on which the
              executable runs, unless that component itself accompanies the executable.

              If  distribution of executable or object code is made by offering access to copy from a designated
              place, then offering equivalent access to copy the source code  from  the  same  place  counts  as
              distribution  of  the  source code, even though third parties are not compelled to copy the source
              along with the object code.

                4. You may not copy, modify, sublicense, or distribute the Program except as expressly  provided
              under  this  License.  Any attempt otherwise to copy, modify, sublicense or distribute the Program
              is void, and will automatically terminate your rights under this License.   However,  parties  who
              have  received  copies,  or  rights,  from  you  under  this  License will not have their licenses
              terminated so long as such parties remain in full compliance.

                5. You are not required to accept this License, since you have not signed it.  However,  nothing
              else  grants  you  permission  to modify or distribute the Program or its derivative works.  These
              actions are prohibited by law if you do not accept  this  License.   Therefore,  by  modifying  or
              distributing  the Program (or any work based on the Program), you indicate your acceptance of this
              License to do so, and all its terms and conditions for  copying,  distributing  or  modifying  the
              Program or works based on it.

                6.  Each  time  you  redistribute  the Program (or any work based on the Program), the recipient
              automatically receives a license from the original licensor to  copy,  distribute  or  modify  the
              Program subject to these terms and conditions.  You may not impose any further restrictions on the
              recipients' exercise of the  rights  granted  herein.   You  are  not  responsible  for  enforcing
              compliance by third parties to this License.

                7.  If,  as  a  consequence  of a court judgment or allegation of patent infringement or for any
              other reason (not limited to patent issues), conditions are  imposed  on  you  (whether  by  court
              order,  agreement or otherwise) that contradict the conditions of this License, they do not excuse
              you from the conditions of this License.  If you cannot distribute so as to satisfy simultaneously
              your obligations under this License and any other pertinent obligations, then as a consequence you
              may not distribute the Program at all.  For example, if a patent license would not permit royalty-
              free  redistribution of the Program by all those who receive copies directly or indirectly through
              you, then the only way you could satisfy both it and this License would  be  to  refrain  entirely
              from distribution of the Program.

              If any portion of this section is held invalid or unenforceable under any particular circumstance,
              the balance of the section is intended to apply and the section as a whole is intended to apply in
              other circumstances.

              It  is  not  the  purpose  of this section to induce you to infringe any patents or other property
              right claims or to contest validity of any such claims; this  section  has  the  sole  purpose  of
              protecting  the integrity of the free software distribution system, which is implemented by public
              license practices.  Many people have made generous contributions to the  wide  range  of  software
              distributed  through that system in reliance on consistent application of that system; it is up to
              the author/donor to decide if he or she is willing to distribute software through any other system
              and a licensee cannot impose that choice.

              This section is intended to make thoroughly clear what is believed to be a consequence of the rest
              of this License.

                8. If the distribution and/or use of the Program is restricted in certain  countries  either  by
              patents  or  by copyrighted interfaces, the original copyright holder who places the Program under
              this License may add an explicit geographical distribution limitation excluding  those  countries,
              so  that  distribution  is  permitted only in or among countries not thus excluded.  In such case,
              this License incorporates the limitation as if written in the body of this License.

                9. The Free Software Foundation may publish revised and/or new versions of  the  General  Public
              License  from  time  to time.  Such new versions will be similar in spirit to the present version,
              but may differ in detail to address new problems or concerns.

              Each version is given a distinguishing version number.  If the Program specifies a version  number
              of  this License which applies to it and "any later version", you have the option of following the
              terms and conditions either of that version or of any later version published by the Free Software
              Foundation.   If the Program does not specify a version number of this License, you may choose any
              version ever published by the Free Software Foundation.

                10. If you wish to incorporate parts of the Program into other free programs whose  distribution
              conditions  are  different,  write  to  the  author  to ask for permission.  For software which is
              copyrighted by the Free Software Foundation, write to the Free Software Foundation;  we  sometimes
              make  exceptions  for  this.   Our decision will be guided by the two goals of preserving the free
              status of all derivatives of our free software and of promoting the sharing and reuse of  software
              generally.

                                          NO WARRANTY

                11. BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY FOR THE PROGRAM, TO THE
              EXTENT PERMITTED BY APPLICABLE LAW.  EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS
              AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR
              IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS  FOR
              A  PARTICULAR  PURPOSE.   THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH
              YOU.  SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY  SERVICING,  REPAIR
              OR CORRECTION.

                12.  IN  NO  EVENT  UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING WILL ANY COPYRIGHT
              HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR REDISTRIBUTE THE PROGRAM AS PERMITTED  ABOVE,  BE
              LIABLE  TO  YOU  FOR  DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES
              ARISING OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF  DATA
              OR  DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD PARTIES OR A FAILURE OF THE
              PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS  BEEN  ADVISED
              OF THE POSSIBILITY OF SUCH DAMAGES.

                                   END OF TERMS AND CONDITIONS

                          How to Apply These Terms to Your New Programs

                If  you develop a new program, and you want it to be of the greatest possible use to the public,
              the best way to achieve this is to make it free  software  which  everyone  can  redistribute  and
              change under these terms.

                To do so, attach the following notices to the program.  It is safest to attach them to the start
              of each source file to most effectively convey the exclusion of warranty;  and  each  file  should
              have at least the "copyright" line and a pointer to where the full notice is found.

                  <one line to give the program's name and a brief idea of what it does.>
                  Copyright (C) <year>  <name of author>

                  This program is free software; you can redistribute it and/or modify
                  it under the terms of the GNU General Public License as published by
                  the Free Software Foundation; either version 2 of the License, or
                  (at your option) any later version.

                  This program is distributed in the hope that it will be useful,
                  but WITHOUT ANY WARRANTY; without even the implied warranty of
                  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
                  GNU General Public License for more details.

                  You should have received a copy of the GNU General Public License
                  along with this program; if not, write to the Free Software
                  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

              Also add information on how to contact you by electronic and paper mail.

              If  the  program  is  interactive,  make  it  output a short notice like this when it starts in an
              interactive mode:

                  Gnomovision version 69, Copyright (C) year name of author
                  Gnomovision comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
                  This is free software, and you are welcome to redistribute it
                  under certain conditions; type `show c' for details.

              The hypothetical commands `show w' and `show c' should show the appropriate parts of  the  General
              Public  License.   Of course, the commands you use may be called something other than `show w' and
              `show c'; they could even be mouse-clicks or menu items--whatever suits your program.

              You should also get your employer (if you work as a programmer) or your school, if any, to sign  a
              "copyright disclaimer" for the program, if necessary.  Here is a sample; alter the names:

                Yoyodyne, Inc., hereby disclaims all copyright interest in the program
                `Gnomovision' (which makes passes at compilers) written by James Hacker.

                <signature of Ty Coon>, 1 April 1989
                Ty Coon, President of Vice

              This  General Public License does not permit incorporating your program into proprietary programs.
              If your program is a subroutine library, you  may  consider  it  more  useful  to  permit  linking
              proprietary  applications  with  the library.  If this is what you want to do, use the GNU Library
              General Public License instead of this License.

       RASLIC If you do not use the GPL, the following license terms apply:

              RasMol License

              Even though the authors of the various documents and software found here have made  a  good  faith
              effort  to  ensure  that the documents are correct and that the software performs according to its
              documentation, and we would greatly appreciate hearing of any  problems  you  may  encounter,  the
              programs  and  documents  any  files  created  by  the programs are provided **AS IS** without any
              warranty as to correctness, merchantability or fitness for any particular or general use.

              THE RESPONSIBILITY FOR ANY ADVERSE CONSEQUENCES FROM THE USE OF PROGRAMS OR DOCUMENTS OR ANY  FILE
              OR FILES CREATED BY USE OF THE PROGRAMS OR DOCUMENTS LIES SOLELY WITH THE USERS OF THE PROGRAMS OR
              DOCUMENTS OR FILE OR FILES AND NOT WITH AUTHORS OF THE PROGRAMS OR DOCUMENTS.

              Subject to your acceptance of the conditions stated above, and your  respect  for  the  terms  and
              conditions  stated  in the notices below, if you are not going to make any modifications or create
              derived works, you are given permission to freely copy and distribute this package,  provided  you
              do the following:

                1.   Either  include  the  complete  documentation,  especially  the  file NOTICE, with what you
              distribute or provide a clear indication where people can get a copy of the documentation; and

                2.  Please give credit where credit is due citing the version and original authors properly; and

                3.  Please do not give anyone the impression that the original authors are providing a  warranty
              of any kind.

              If  you  would  like  to  use  major pieces of RasMol in some other program, make modifications to
              RasMol, or in some other way make what a lawyer would call a "derived  work",  you  are  not  only
              permitted  to  do  so,  you are encouraged to do so. In addition to the things we discussed above,
              please do the following:

                4.  Please explain in your documentation how what you did differs from this version  of  RasMol;
              and

                5.  Please make your modified source code available.

              This  version  of RasMol is _not_ in the public domain, but it is given freely to the community in
              the hopes of advancing science.  If you make changes, please make them in  a  responsible  manner,
              and please offer us the opportunity to include those changes in future versions of RasMol.

       General Notice
              The following notice applies to this work as a whole and to the works included within it:

              *  Creative  endeavors  depend  on  the lively exchange of ideas. There are laws and customs which
              establish rights and responsibilities for authors and the  users  of  what  authors  create.  This
              notice  is  not intended to prevent you from using the software and documents in this package, but
              to ensure that there are no misunderstandings about terms and conditions of such use.

              * Please read the following notice carefully. If you do not understand any portion of this notice,
              please  seek appropriate professional legal advice before making use of the software and documents
              included in this software package. In addition to whatever other steps you may be obliged to  take
              to respect the intellectual property rights of the various parties involved, if you do make use of
              the software and documents in this package, please give credit where credit is due by citing  this
              package, its authors and the URL or other source from which you obtained it, or equivalent primary
              references in the literature with the same authors.

              * Some of the software and documents included within this software package  are  the  intellectual
              property of various parties, and placement in this package does not in any way imply that any such
              rights have in any way been waived or diminished.

              * With respect to any software or documents for which a copyright exists, ALL RIGHTS ARE  RESERVED
              TO THE OWNERS OF SUCH COPYRIGHT.

              *  Even though the authors of the various documents and software found here have made a good faith
              effort to ensure that the documents are correct and that the software performs  according  to  its
              documentation,  and  we  would  greatly  appreciate hearing of any problems you may encounter, the
              programs and documents and any files created by the programs are provided **AS  IS**  without  any
              warranty as to correctness, merchantability or fitness for any particular or general use.

              *  THE  RESPONSIBILITY  FOR  ANY ADVERSE CONSEQUENCES FROM THE USE OF PROGRAMS OR DOCUMENTS OR ANY
              FILE OR FILES CREATED BY USE OF THE PROGRAMS OR DOCUMENTS  LIES  SOLELY  WITH  THE  USERS  OF  THE
              PROGRAMS OR DOCUMENTS OR FILE OR FILES AND NOT WITH AUTHORS OF THE PROGRAMS OR DOCUMENTS.

              See the files GPL and RASLIC for two alternate ways to license this package.

       RasMol V2.6 Notice
              The following notice applies to RasMol V 2.6 and older RasMol versions.

              Information  in  this  document  is  subject  to  change  without  notice and does not represent a
              commitment on the part of the supplier. This package is sold/distributed subject to the  condition
              that  it  shall  not,  by  way  of  trade  or  otherwise, be lent, re-sold, hired out or otherwise
              circulated without the supplier's prior consent, in any form of packaging or cover other than that
              in  which  it  was  produced.  No  part of this manual or accompanying software may be reproduced,
              stored in a retrieval system on optical or magnetic disk, tape or any other medium, or transmitted
              in  any form or by any means, electronic, mechanical, photocopying, recording or otherwise for any
              purpose other than the purchaser's personal use.

              This product is not to be used in the planning, construction, maintenance, operation or use of any
              nuclear  facility  nor  the  flight,  navigation  or  communication  of aircraft or ground support
              equipment. The author shall not be liable, in whole or in part, for any claims or damages  arising
              from such use, including death, bankruptcy or outbreak of war.

       IUCR Policy
              The  IUCr  Policy  for  the  Protection  and  the Promotion of the STAR File and CIF Standards for
              Exchanging and Archiving Electronic Data.

              Overview

              The  Crystallographic  Information  File  (CIF)[1]  is  a  standard  for  information  interchange
              promulgated  by the International Union of Crystallography (IUCr). CIF (Hall, Allen & Brown, 1991)
              is the recommended method for submitting publications to  Acta  Crystallographica  Section  C  and
              reports  of  crystal structure determinations to other sections of Acta Crystallographica and many
              other journals. The syntax of a CIF is a subset of the more general STAR File[2] format.  The  CIF
              and  STAR  File  approaches are used increasingly in the structural sciences for data exchange and
              archiving, and are having a significant influence on these activities in other fields.

              Statement of intent

              The IUCr's interest in the STAR File is as a general data interchange standard  for  science,  and
              its  interest  in the CIF, a conformant derivative of the STAR File, is as a concise data exchange
              and archival standard for crystallography and structural science.

              Protection of the standards

              To protect the STAR File and the CIF as standards for interchanging and archiving electronic data,
              the IUCr, on behalf of the scientific community,

                 * holds the copyrights on the standards themselves,

                 * owns the associated trademarks and service marks, and

                 * holds a patent on the STAR File.

              These  intellectual  property  rights  relate  solely  to the interchange formats, not to the data
              contained therein, nor to the software used in the generation, access or manipulation of the data.

              Promotion of the standards

              The sole requirement that the IUCr, in its protective role,  imposes  on  software  purporting  to
              process  STAR  File  or  CIF  data  is  that  the  following  conditions  be  met prior to sale or
              distribution.

                 * Software claiming to read files written to either the STAR File or the CIF standard  must  be
              able  to  extract  the  pertinent  data from a file conformant to the STAR File syntax, or the CIF
              syntax, respectively.

                 * Software claiming to write files in either the STAR File, or the CIF, standard  must  produce
              files that are conformant to the STAR File syntax, or the CIF syntax, respectively.

                 *  Software  claiming  to read definitions from a specific data dictionary approved by the IUCr
              must be able to extract any pertinent definition which is conformant to the dictionary  definition
              language (DDL)[3] associated with that dictionary.

              The  IUCr,  through  its  Committee  on  CIF  Standards,  will assist any developer to verify that
              software meets these conformance conditions.

              Glossary of terms

              [1] CIF:

              is  a  data  file  conformant  to   the   file   syntax   defined   at   http://www.iucr.org/iucr-
              top/cif/spec/index.html

              [2] STAR File:

              is   a   data   file   conformant   to   the  file  syntax  defined  at  http://www.iucr.org/iucr-
              top/cif/spec/star/index.html

              [3] DDL:

              is a language used  in  a  data  dictionary  to  define  data  items  in  terms  of  "attributes".
              Dictionaries  currently  approved  by  the  IUCr,  and  the  DDL  versions used to construct these
              dictionaries, are listed at http://www.iucr.org/iucr-top/cif/spec/ddl/index.html

              Last modified: 30 September 2000

              IUCr Policy Copyright (C) 2000 International Union of Crystallography

       CBFLIB The following Disclaimer Notice applies to CBFlib V0.1, from which this code in part is derived.

              * The items furnished herewith were developed  under  the  sponsorship  of  the  U.S.  Government.
              Neither  the  U.S.,  nor  the  U.S.  D.O.E.,  nor the Leland Stanford Junior University, nor their
              employees, makes any warranty, express or implied, or assumes any liability or responsibility  for
              accuracy,  completeness or usefulness of any information, apparatus, product or process disclosed,
              or represents that its use will not infringe privately-owned rights. Mention of any  product,  its
              manufacturer,  or  suppliers  shall  not,  nor  is it intended to, imply approval, disapproval, or
              fitness for any particular use. The U.S. and the University at all times retain the right  to  use
              and disseminate the furnished items for any purpose whatsoever.

              Notice 91 02 01

       CIFPARSE
              Portions  of  this  software  are  loosely  based on the CIFPARSE software package from the NDB at
              Rutgers University.  See

                 http://ndbserver.rutgers.edu/NDB/mmcif/software

              CIFPARSE is part of the NDBQUERY application, a program component of  the  Nucleic  Acid  Database
              Project [ H. M. Berman, W. K. Olson, D. L. Beveridge, J. K. Westbrook, A. Gelbin, T. Demeny, S. H.
              Shieh, A. R. Srinivasan, and B.  Schneider. (1992). The Nucleic  Acid  Database:  A  Comprehensive
              Relational  Database  of Three-Dimensional Structures of Nucleic Acids. Biophys J., 63, 751-759.],
              whose cooperation is gratefully acknowledged, especially in the form of design concepts created by
              J. Westbrook.

              Please be aware of the following notice in the CIFPARSE API:

              This  software is provided WITHOUT WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE
              OR ANY OTHER WARRANTY, EXPRESS OR IMPLIED. RUTGERS MAKE NO REPRESENTATION  OR  WARRANTY  THAT  THE
              SOFTWARE WILL NOT INFRINGE ANY PATENT, COPYRIGHT OR OTHER PROPRIETARY RIGHT.

DESCRIPTION

       RasMol  is  a  molecular  graphics  program intended for the visualisation of proteins, nucleic acids and
       small molecules.  The program is aimed at display, teaching and generation of publication quality images.
       RasMol  runs  on  wide  range  of  architectures and operating systems including Microsoft Windows, Apple
       Macintosh, UNIX and VMS systems. UNIX and VMS versions require an 8,  24  or  32  bit  colour  X  Windows
       display (X11R4 or later).  The X Windows version of RasMol provides optional support for a hardware dials
       box and accelerated shared memory communication (via the XInput and MIT-SHM extensions) if  available  on
       the current X Server.

       The  program reads in a molecule coordinate file and interactively displays the molecule on the screen in
       a variety of colour schemes and molecule representations.  Currently  available  representations  include
       depth-cued  wireframes,  'Dreiding'  sticks, spacefilling (CPK) spheres, ball and stick, solid and strand
       biomolecular ribbons, atom labels and dot surfaces.

       Up to 5 molecules may be loaded and displayed at once.  Any one or all of
        the molecules may be rotated and translated.

       The RasMol help facility can be accessed by typing "help <topic>" or "help <topic> <subtopic>"  from  the
       command  line.  A  complete  list of RasMol commands may be displayed by typing "help commands". A single
       question mark may also be used to  abbreviate  the  keyword  "help".   Please  type  "help  notices"  for
       important notices.

COMMANDS

       RasMol  allows  the execution of interactive commands typed at the RasMol> prompt in the terminal window.
       Each command must be given on a separate line. Keywords are case insensitive and may be entered in either
       upper  or lower case letters. All whitespace characters are ignored except to separate keywords and their
       arguments.

       All commands may be prefixed by a parenthesized atom expression to temporarily select certain atoms  just
       for  the  execution  of  that  one  command.   After  execution of the command, the previous selection is
       restored except for the commands select , restrict and script.

       The commands/keywords currently recognised by RasMol are given below.

       Backbone
              The RasMol backbone command permits the representation of a polypeptide backbone as  a  series  of
              bonds  connecting  the  adjacent alpha carbons of each amino acid in a chain. The display of these
              backbone 'bonds' is turned on and off by the command  parameter  in  the  same  way  as  with  the
              wireframe  command.  The  command  backbone off turns off the selected 'bonds', and backbone on or
              with a number turns them on. The number can  be  used  to  specify  the  cylinder  radius  of  the
              representation  in  either  Angstrom  or RasMol units. A parameter value of 500 (2.0 Angstroms) or
              above results in a "Parameter value too large" error. Backbone objects may be coloured  using  the
              RasMol colour backbone command.

              The  reserved  word  backbone is also used as a predefined set ("help sets") and as a parameter to
              the set hbond and set ssbond commands. The RasMol command trace renders a  smoothed  backbone,  in
              contrast to backbone which connects alpha carbons with straight lines.

              The backbone may be displayed with dashed lines by use of the backbone dash command.

       Background
              The RasMol background command is used to set the colour of the "canvas" background. The colour may
              be given as either a colour name or a  comma  separated  triple  of  Red,  Green  and  Blue  (RGB)
              components  enclosed  in  square brackets. Typing the command help colours will give a list of the
              predefined colour names  recognised  by  RasMol.   When  running  under  X  Windows,  RasMol  also
              recognises colours in the X server's colour name database.

              The background command is synonymous with the RasMol set background command.

       Bond   The  RasMol  command  bond <number> <number> + adds the designated bond to the drawing, increasing
              the bond order if the bond already exists.  The command bond <number> <number>  pick  selects  the
              two  atoms  specified by the atom serial numbers as the two ends of a bond around which the rotate
              bond <angle> command will be applied.  If no bond exists, it is created.

              Rotation around a previously picked bond may be specified by the rotate bond <angle>  command,  or
              may  also be controlled with the mouse, using the bond rotate on/off or the equivalent rotate bond
              on/off commands.

       Bulgarian
              The RasMol Bulgarian command sets the menus and messages to the Bulgarian versions.

              This command may not work correctly unless appropriate fonts have been  installed.   The  commands
              Bulgarian, Chinese, English, French, Italian, Russian and Spanish may be used to select Bulgarian,
              Chinese, English, French, Italian, Japanese,  Russian  and  Spanish  menus  and  messages  if  the
              appropriate fonts have been installed.

       Cartoon
              The  RasMol  cartoon  command does a display of a molecule ribbons as Richardson (MolScript) style
              protein cartoons, implemented as thick (deep)  ribbons.  The  easiest  way  to  obtain  a  cartoon
              representation of a protein is to use the Cartoons option on the Display menu. The cartoon command
              represents the currently selected residues as a deep ribbon with width specified by the  command's
              argument.   Using  the  command without a parameter results in the ribbon's width being taken from
              the protein's secondary structure, as described in the ribbons command. By default, the  C-termini
              of  beta-sheets  are  displayed  as  arrow  heads.  This may be enabled and disabled using the set
              cartoons command.  The depth of the cartoon may  be  adjusted  using  the  set  cartoons  <number>
              command.  The  set  cartoons  command  without  any  parameters returns these two options to their
              default values.

       Centre The RasMol centre command defines the point about which the rotate command  and  the  scroll  bars
              rotate  the current molecule. Without a parameter the centre command resets the centre of rotation
              to be the centre of gravity of the molecule. If an atom expression is  specified,  RasMol  rotates
              the  molecule  about the centre of gravity of the set of atoms specified by the expression. Hence,
              if a single atom is specified by  the  expression,  that  atom  will  remain  'stationary'  during
              rotations.

              Type help expression for more information on RasMol atom expressions.

              Alternatively  the centring may be given as a comma separated triple of [CenX, CenY, CenZ] offsets
              in RasMol units (1/250 of an Angstrom) from the centre of gravity.  The triple must be enclosed in
              square brackets.

              The  optional  forms  centre  ...  translate and centre ... center may be used to specify use of a
              translated centre of rotation (not necessarily in the  centre  of  the  canvas)  or  a  centre  of
              rotation  which is placed at the centre of the canvas.  Starting with RasMol 2.7.2, the default is
              to center the new axis on the canvas.

       Chinese
              The RasMol Chinese command sets the menus and messages to the Chinese versions.

              This command may not work correctly unless appropriate fonts have been  installed.   The  commands
              Bulgarian, Chinese, English, French, Italian, Russian and Spanish may be used to select Bulgarian,
              Chinese, English, French, Italian, Japanese,  Russian  and  Spanish  menus  and  messages  if  the
              appropriate fonts have been installed.

       Clipboard
              The  RasMol clipboard command places a copy of the currently displayed image on the local graphics
              'clipboard'. Note: this command is not yet supported on UNIX or VMS machines. It  is  intended  to
              make  transferring  images  between  applications  easier  under  Microsoft Windows or on an Apple
              Macintosh.

              When using RasMol on a UNIX or VMS system this functionality  may  be  achieved  by  generating  a
              raster image in a format that can be read by the receiving program using the RasMol write command.

       Colour Colour  the  atoms  (or other objects) of the selected region. The colour may be given as either a
              colour name or a comma separated triple of Red, Green and Blue (RGB) components enclosed in square
              brackets.  Typing  the  command  help  colours will give a list of all the predefined colour names
              recognised by RasMol.

              Allowed objects are atoms, bonds, backbone, ribbons, labels, dots, hbonds, map, and  ssbonds.   If
              no  object is specified, the default keyword atom is assumed.  Some colour schemes are defined for
              certain object types. The colour scheme none can be applied to all objects except atoms and  dots,
              stating  that  the  selected  objects  have  no  colour  of their own, but use the colour of their
              associated atoms (i.e. the atoms they connect).  Atom objects can also be coloured by alt,  amino,
              chain,  charge,  cpk,  group,  model, shapely, structure, temperature or user.  Hydrogen bonds can
              also be coloured by type and dot surfaces can also be coloured by  electrostatic  potential.   For
              more  information  type help colour <colour>.  Map objects may be coloured by specific color of by
              nearest atom.

       ColourMode
              ColourMode allows the user to switch between using the new colour  method.  At  present,  the  new
              coloring  technique is the same as the old one, but to preserve compatibility for older scripts it
              may be wise to add a "colormode on" near the top of your  script  somewhere,  if  the  script  was
              designed for version 2.7.3 of RasMol or earlier. The new color method, when completed, aims to fix
              a few bugs in the coloring routines.

       Connect
              The RasMol connect command is used to force  RasMol  to  (re)calculate  the  connectivity  of  the
              current  molecule.   If  the  original  input  file  contained  connectivity  information, this is
              discarded. The command connect false  uses  a  fast  heuristic  algorithm  that  is  suitable  for
              determining bonding in large bio-molecules such as proteins and nucleic acids. The command connect
              true uses a slower more accurate algorithm based upon covalent radii  that  is  more  suitable  to
              small  molecules  containing  inorganic  elements  or  strained rings. If no parameters are given,
              RasMol determines which algorithm to use based on the number of atoms in the input  file.  Greater
              than  255  atoms  causes  RasMol  to  use  the  faster  implementation. This is the method used to
              determine bonding, if necessary, when a molecule is first read in using the load command.

       Defer  The RasMol defer command adds the command given to the macro with given name, if no name is given,
              the  command  is  added to the macro with a blank name. The command zap is a special case. In that
              case the macro is erased. If no name is given the command must begin with a selection, e.g.  defer
              (selection).spacefill

              The deferred commands accumulated under the given name can be executed using the execute command

       Define The  RasMol  define  command  allows the user to associate an arbitrary set of atoms with a unique
              identifier. This allows the definition of user-defined sets. These sets are  declared  statically,
              i.e.  once  defined  the  contents  of the set do not change, even if the expression defining them
              depends on the current transformation and representation of the molecule.

       Depth  The RasMol depth command enables, disables or positions the back-clipping plane of  the  molecule.
              The  program  only  draws  those  portions  of the molecule that are closer to the viewer than the
              clipping plane.  Integer values range from zero at the very back of the molecule to 100  which  is
              completely  in front of the molecule. Intermediate values determine the percentage of the molecule
              to be drawn.

              This command interacts with the slab <value> command, which clips to  the  front  of  a  given  z-
              clipping plane.

       Dots   The  RasMol  dots  command  is  used to generate a van der Waals' dot surface around the currently
              selected atoms. Dot surfaces display regularly spaced points on a sphere of van der Waals'  radius
              about  each  selected  atom.  Dots that would are 'buried' within the van der Waals' radius of any
              other atom (selected or not) are not displayed.  The command dots  on  deletes  any  existing  dot
              surface  and  generates  a  dots surface around the currently selected atom set with a default dot
              density of 100. The command dots off deletes any existing dot surface.  The  dot  density  may  be
              specified  by  providing  a  numeric  parameter  between  1  and  1000.  This  value approximately
              corresponds to the number of dots on the surface of a medium sized atom.

              By default, the colour of each point on a dot surface is the colour of its  closest  atom  at  the
              time the surface is generated. The colour of the whole dot surface may be changed using the colour
              dots command.

       Echo   The RasMol echo command is used to display a message in the RasMol  command/terminal  window.  The
              string  parameter  may  optionally  be  delimited  in  double quote characters. If no parameter is
              specified, the echo command displays a  blank  line.  This  command  is  particularly  useful  for
              displaying text from within a RasMol script file.

       English
              The RasMol English command sets the menus and messages to the English versions.

              This  command  may  not work correctly unless appropriate fonts have been installed.  The commands
              Bulgarian, Chinese, English, French, Italian, Russian and Spanish may be used to select Bulgarian,
              Chinese,  English,  French,  Italian,  Japanese,  Russian  and  Spanish  menus and messages if the
              appropriate fonts have been installed.

       Execute
              The RasMol execute command:

              1.  saves the old poise of the molecule (translation, rotation and zoom)

              2. executes the specified macro suppressing both screen updates and recording

              3. animates motion of the newly rendered molecule linearly from the old poise to the new poise

              The macro must have been previously defined by calls to the defer command.

              The animation of the motion depends on the prior settings of the record command.

       French The RasMol French command sets the menus and messages to the French versions.

              This command may not work correctly unless appropriate fonts have been  installed.   The  commands
              Bulgarian, Chinese, English, French, Italian, Russian and Spanish may be used to select Bulgarian,
              Chinese, English, French, Italian, Japanese,  Russian  and  Spanish  menus  and  messages  if  the
              appropriate fonts have been installed.

       HBonds The  RasMol  hbond  command  is  used  to represent the hydrogen bonding of the protein molecule's
              backbone. This information is useful in assessing  the  protein's  secondary  structure.  Hydrogen
              bonds are represented as either dotted lines or cylinders between the donor and acceptor residues.
              The first time the hbond command is used, the program searches the structure of  the  molecule  to
              find  hydrogen  bonded residues and reports the number of bonds to the user. The command hbonds on
              displays the selected 'bonds' as dotted lines, and the hbonds off turns  off  their  display.  The
              colour  of hbond objects may be changed by the colour hbond command. Initially, each hydrogen bond
              has the colours of its connected atoms.

              By default the dotted lines are drawn between the accepting oxygen and the donating  nitrogen.  By
              using  the  set  hbonds command the alpha carbon positions of the appropriate residues may be used
              instead. This is especially useful when examining proteins in backbone representation.

       Help   The RasMol help command provides on-line help on the given topic.

       Italian
              The RasMol Italian command sets the menus and messages to the Italian versions.

              This command may not work correctly unless appropriate fonts have been  installed.   The  commands
              Bulgarian, Chinese, English, French, Italian, Russian and Spanish may be used to select Bulgarian,
              Chinese, English, French, Italian, Japanese,  Russian  and  Spanish  menus  and  messages  if  the
              appropriate fonts have been installed.

       Japanese
              The RasMol Japanese command sets the menus and messages to the Japanese versions.

              This  command  may  not work correctly unless appropriate fonts have been installed.  The commands
              Bulgarian, Chinese, English, French, Italian, Russian and Spanish may be used to select Bulgarian,
              Chinese,  English,  French,  Italian,  Japanese,  Russian  and  Spanish  menus and messages if the
              appropriate fonts have been installed.

       Label  The RasMol label command allows an arbitrary formatted text string  to  be  associated  with  each
              currently  selected  atom.   This string may contain embedded 'expansion specifiers' which display
              properties of the atom being labelled. An expansion specifier consists of a '%' character followed
              by a single alphabetic character specifying the property to be displayed.  An actual '%' character
              may be displayed by using the expansion specifier '%%'.

              Atom labelling for the currently selected atoms may be turned off with the command label off.   By
              default,  if  no  string  is  given as a parameter, RasMol uses labels appropriate for the current
              molecule.

              The colour of each label may be changed using the colour label command. By default, each label  is
              drawn  in  the  same  colour  as  the  atom  to  which it is attached. The size and spacing of the
              displayed text may be changed using the set fontsize command.  The width of  the  strokes  in  the
              displayed text may be changed
               using the set fontstroke
               command.

       Load   Load  a  molecule  coordinate  file into RasMol. Valid molecule file formats are pdb (Protein Data
              Bank format), mdl (Molecular Design Limited's MOL file  format),  alchemy  (Tripos'  Alchemy  file
              format),  mol2  (Tripos' Sybyl Mol2 file format), charmm (CHARMm file format), xyz (MSC's XMol XYZ
              file format), mopac (J. P. Stewart's MOPAC file format) or cif (IUCr CIF or mmCIF file format). If
              no  file  format is specified, PDB, CIF, or mmCIF is assumed by default. Up to 20 molecules may be
              loaded at a time.  If CHEM_COMP ligand models are included in an mmCIF file, they will  be  loaded
              as  NMR  models,  first  giving the all the NMR models for model coordinates if specified and then
              giving all the NMR models for ideal model coordinates.

              To delete a molecule prior to loading another use the RasMol zap command.  To  select  a  molecule
              for manipulation use the RasMol molecule <n> command.

              The load command selects all the atoms in the molecule, centres it on the screen and renders it as
              a CPK coloured wireframe model. If the molecule  contains  no  bonds  (i.e.  contains  only  alpha
              carbons),  it  is drawn as an alpha carbon backbone. If the file specifies fewer bonds than atoms,
              RasMol determines connectivity using the connect command.

              The load inline command also allows the storing of atom coordinates in  scripts  to  allow  better
              integration  with  WWW  browsers.  A  load  command  executed inside a script file may specify the
              keyword inline instead of a conventional filename. This option specifies that the  coordinates  of
              the molecule to load are stored in the same file as the currently executing commands.

       Map    The  RasMol  map  commands  manipulate  electron  density maps in coordination with the display of
              molecules.  These commands are very memory intensive and may not work  on  machines  with  limited
              memory.   Each  molecule may have as many maps as available memory permits.  Maps may be read from
              files or generated from Gaussian density distributions around atoms.

              map colour, to colour a map according to a given colour scheme, map generate, to  generate  a  map
              from selected atoms based on pseudo-Gaussians, map level, to set the contouring level for selected
              maps, map load, to load a map from a file, map mask to designate a mask for the selected maps, map
              resolution,  to  set  the  resolution for contouring selected maps, map restrict, to select one or
              more maps and to disable all others, map save, to save map  information  to  a  file,  map  scale,
              control  the  scaling  of pseudo-Gaussians when generating maps, map select, to select one or more
              maps, map show, to display information about one or more maps or about the parameters to  be  used
              in  generating  or  loading  the next map, map spacing, to set the spacing betwen contour lines of
              selected maps, map spread, to set the variance of the Gaussians for map generation as  a  fraction
              of the atomic radius, and map zap to delete previously generated or loaded maps.

              The  effect of map generate and map load commands is modified by the map mask command which limits
              the portion of the display space that can be considered for display of maps.

       Map colour
              The RasMol map colour command colours the selected maps according to the specified colour  scheme.
              The colour scheme may be a colour name or and RBG triple in brackets, or the keyword atom to cause
              the map points to be coloured by the color of the nearest atom.

       Map generate
              The RasMol map generate command generates a map from whatever atoms  are  currently  selected,  by
              summing electron densities approximated by Gaussian distributions.  The height of each Gaussian is
              determined by the setting of the map scale command.  In  the  default  of  map  scale  true,  each
              Gaussian  has  a height proportional element type of the atom.  If the optional 'LRSurf' parameter
              is given or if map scale false has been executed, each Gaussian is scaled  so  that  the  Gaussian
              contour level 1 is at the van der Waals radius.  In either case a standard deviation determined by
              the most recently specified spread or resolution is used.  If a non-zero spread has been given the
              radius  of  the  atom  is multiplied by the spread to find the standard deviation.  The default is
              2/3rds.  If a resolution has been given, the spread is inferred as 2/3rds of the resolution.

              For example, if the resolution is given as 1., and the atom in question is a Carbon with a van der
              Waals  radius  of 468 RasMol units (1.87 Angstroms), the inferred spead is .6667, and the standard
              deviation of the Gaussian is taken as 1.25 Angstroms.

              If the spread has been set to zero, the spread for each atom is determined from the van der  Waals
              radius and the probe atom radius to simulate the effect of a Lee-Richards surface.

              If  no  specific  map  was  given by the map selector, the new map is given the next available map
              number.

              If a specific map was given by the map selector, the new map replaces that map.  If more than  one
              map  was given by the map selector, the new map replaces the lowest numbered of the selected maps.
              In any case the new map becomes the currently selected map.

              The map is displayed as dots, mesh or a surface, depending on the last map rendering mode selected
              or the mode selected on the command itself.

       Map level
              The  RasMol  map  level  command  sets  the  contour  level  to  be  used  in  creating subsequent
              representations of generated or loaded maps.  If the keyword MEAN in used the level is relative to
              the mean of the map data.  Otherwise the level is absolute.

              In general, a lower level results in a map containing more of the displayed volume, while a higher
              level results in a map containing less of the displayed volume.

       Map load
              The RasMol map load command loads a map file into RasMol.  The valid formats are CCP4  map  format
              and imgCIF format.

              If  no  specific  map  was  given by the map selector, the new map is given the next available map
              number.

              If a specific map was given by the map selector, the new map replaces that map.  If more than  one
              map  was given by the map selector, the new map replaces the lowest numbered of the selected maps.
              In any case the new map becomes the currently selected map.

              The map is displayed as dots, mesh or a surface depending on the last map rendering mode selected.

       Map mask
              The RasMol map mask command specifies a mask to be used to limit the display space to be used  for
              making representations of other maps or removes an earlier mask specification.

              The  'selected' option indicates that the mask is to be created from the currently selected atoms.
              The '<number>' option indicates that the mask  is  to  be  copied  from  the  map  of  the  number
              specified.  The 'none' option removes the previously specified mask, if any.

              The  map  selector  specifies  the  map or maps to which the specified mask will the applied.  For
              example, 'map next mask selected' specifies that the currently selected atoms are to  be  used  to
              generate  a  mask  to  be  applied  to any maps created by subsequent 'map load' or 'map generate'
              commands.

              Any map may be used as a mask.  The portions of the mask map greater than than  or  equal  to  the
              average  value  of the mask map allow the values of the map being masked to be used as given.  The
              portions of the mask map lower than the average value of the mask map cause the values of the  map
              being masked to be treated as if they were equal to the lowest data value of the map being masked.

       Map resolution
              The  RasMol  map  resolution  command  specifies  the  resolution  in RasMol units or, if a number
              containing a decimal point is given, the resolution in Angstroms to be used in generating  and  in
              representing maps.

              The  resolution  is used at the map spacing for representations of maps, indicating the separation
              between contour levels (see the map spacing command) and to infer the map spread  to  be  used  in
              generated  maps  from  selected  atoms (see the map spread command).  The map spread is set to two
              thirds of the specified resolution.

       Map restrict
              The RasMol map restrict command selects particular maps to make them  active  for  subsequent  map
              commands.   This  is  similar to the map select command, but does disables the display of the maps
              that were not selected.

       Map save
              The RasMol map save command saves an imgCIF map file.

              If no specific map was given by the map selector, the currently selected maps and their masks  are
              written to the file, one map and mask pair per data block.

       Map scale
              The RasMol map scale command selects the scaling of pseudo-Gaussians in the map generate commands.
              In the default of map scale true, each Gaussian has a height  proportional  element  type  of  the
              atom.   If map scale false has been executed, each Gaussian is scaled so that the Gaussian contour
              level 1 is at the van der Waals radius.  In either case a standard  deviation  determined  by  the
              most recently specified spread or resolution is used.

       Map select
              The  RasMol  map  select  command  selects  particular maps to make them active for subsequent map
              commands.  This is similar to the map restrict command, but does not disable the  display  of  the
              maps that were not selected.

              If the optional atom parameter is given, the command selects the atoms with centres closest to the
              map points.  The radius of the search may  be  specified  by  the  parameter  search_radius.   The
              default  is  to  look  for atoms within 4 Angstroms plus the probe radius.  If the optional within
              parameter is given, the new selection is taken from within the currently selected atoms.   If  the
              options  add  parameter is given, the new selection is added to the currently selected atoms.  The
              default is to search within all atoms.

       Map show
              The RasMol map show command causes information about the maps specified by the map selector to  be
              written to the command window.

       Map spacing
              The  RasMol map spacing command specifies the spacing to be used between contour lines in creating
              representations of maps.  The spacing is typically
               given in Angstroms with a decimal point, but may also be specified in RasMol units (250ths of  an
              Angstom)  as an integer.  For maps loaded in grid coordinates that spacing is parallel to the cell
              edges.  The default spacing is one half Angstrom.

       Map spread
              The RasMol map spread command specifies the reciprocal of the number of  standard  deviations  per
              radius  to  be  used  in  generating  maps as sums of Gaussians centered on atomic positions.  The
              default spread is one two thirds (i.e. each radius covers 1.5 standard deviations).

              If the spread has been set to zero, the spread for each atom is determined from the van der  Waals
              radius and the probe atom radius to simulate the effect of a Lee-Richards surface.

       Map zap
              The  RasMol  map zap command removes the data and representations of the maps specified by the map
              selector.  The map numbers of maps that have not been removed are not changed.

       Molecule
              The RasMol molecule command selects one  of  up  to  5  previously  loaded  molecules  for  active
              manipulation.   While  all  the  molcules  are  displayed and may be rotated collectively (see the
              rotate all command), only one molecule at a time time is active for manipulation by  the  commands
              which control the details of rendering.

       Monitor
              The RasMol monitor command allows the display of distance monitors. A distance monitor is a dashed
              (dotted) line between an arbitrary pair of atoms, optionally  labelled  by  the  distance  between
              them.   The  RasMol command monitor <number> <number> adds such a distance monitor between the two
              atoms specified by the atom serial numbers given as parameters

              Distance monitors are turned off with the command monitors off.  By default, monitors display  the
              distance between its two end points as a label at the centre of the monitor. These distance labels
              may be turned off with the command set monitors off, and re-enabled with the command set  monitors
              on.   Like most other representations, the colour of a monitor is taken from the colour of its end
              points unless specified by the colour monitors command.

              Distance monitors may also be added to a molecule interactively with  the  mouse,  using  the  set
              picking monitor command. Clicking on an atom results in its being identified on the rasmol command
              line. In addition every atom picked increments a modulo counter such that, in monitor mode,  every
              second  atom  displays  the  distance between this atom and the previous one. The shift key may be
              used to form distance monitors between a fixed atom and several consecutive positions. A  distance
              monitor  may  also  be  removed  (toggled)  by selecting the appropriate pair of atom end points a
              second time.

       Notoggle
              The RasMol NoToggle command enables or disables the use of the toggle ability that is used by some
              of the other RasMol commands.  When no boolean value is specified, NoToggle mode is ENABLED.  When
              NoToggle mode is ENABLED, all  toggle  functionality  is  DISABLED.  To  turn  it  off,  one  must
              explicitly set notoggle off.

              Some  commands  which  use  the  toggle feature are: ColourMode.  More functions that utilize this
              capability may be added at a later date.

       Pause  The RasMol pause command is used in script files to stop the script file for local manipulation by
              a mouse, until any key is pushed to restart the script file.  Wait is synonymous with pause.  This
              command may be executed in RasMol script files to suspend the sequential execution of commands and
              allow  the  user  to examine the current image.   When RasMol executes a pause command in a script
              file, it suspends  execution of the rest of the file, refreshes the image on the screen and allows
              the  manipulation  of  the  image  using  the  mouse and scroll  bars, or resizing of the graphics
              window.  Once a key is pressed, control returns to the script file at the line following the pause
              command.  While a script is suspended the molecule may be rotated, translated, scaled, slabbed and
              picked as usual, but all menu commands are disabled.

       Play   The RasMol play command specifies the recording medium from which  to  play  back  a  movie.   The
              playback  frame  start time is given in seconds to millisecond precision.  Since we are working on
              computers, the medium is specified as a set of files, each marked with the  playback  frame  start
              time  in milliseconds as part of the name. The place in the name at which to look for the playback
              frame start time in milliseconds is marked by the characters "ssssss" with an  appropriate  number
              of  digits.  RasMol accepts either upper or lower case s's or decimal digits to mark the place for
              the time.  The play off and play eject commands effectively remove the specified medium from  use.
              If  no  medium is specified, play off suspends playing and play on resumes playing.  Normally play
              starts immediately and runs to the end of  the  medium.  However,  if  play  off  and/or  or  some
              combination of play from and play until is entered before play type medium, those settings will be
              used.

              As of release 2.7.5, RasMol support play from scripts and data files.

       Print  The RasMol print command sends the currently displayed image to the local  default  printer  using
              the  operating  system's native printer driver. Note: this command is not yet supported under UNIX
              or VMS. It is intended to take advantage of Microsoft Windows and Apple Macintosh printer drivers.
              For example, this allows images to be printed directly on a dot matrix printer.

              When  using RasMol on a UNIX or VMS system this functionality may be achieved by either generating
              a PostScript file using the RasMol write  ps  or  write  vectps  commands  and  printing  that  or
              generating a raster image file and using a utility to dump that to the local printer.

       Quit   Exit  from  the  RasMol  program.  The RasMol commands exit and quit are synonymous, except within
              nested scripts.  In that case, exit terminates only the current level, while quit  terminates  all
              nested levels of scripts.

       Record The  RasMol  record command specifies the recording medium to hold the movie. Since we are working
              on computers, the medium is specified as a template for a set  of  files,  each  marked  with  the
              playback  frame  start  time  in milliseconds (rather than as seconds to avoid embedding a decimal
              point) as part of the name. The place in the name to be replaced with  the  playback  frame  start
              time  in  milliseconds  is marked by the characters "ssssss" with an appropriate number of digits.
              RasMol accepts either upper or lower case s's or decimal digits to mark the place  for  the  time.
              The  record  off  commands remove the specified medium from use. If no medium is specified, record
              off suspends recording and record on resumes recording with the next available time  on  the  same
              medium.  The  screen  is  the  default  medium  and  is,  by  default, on. Writing to disk must be
              explicitly specified so that the disk does not get  filled  up  unintentionally.  The  type  of  a
              recording  medium may be an image type such as gif, pict or png to record the actual screen images
              or script to record the RasMol commands used to generate the frames.

              Normally recording starts at playback frame start time 0 seconds.  A  non-zero  starting  time  in
              seconds can be specified with the record from command as in record from 25 or record from 37.25 to
              help in organizing scenes of movies to be assembled later in an  appropriate  order.   The  record
              until  command  allows  an  upper limit to be set on recording time in seconds.  The default is to
              have no limit. Issuing the commands

              record from 600

              record until 1800

              would result in a 20 minute movie segment intended to start 10 minutes into a longer movie.  These
              commands allow control over rewriting selected time segments.

       Refresh
              The  RasMol  refresh  command  redraws  the  current  image.   This is useful in scripts to ensure
              application of a complex list of parameter changes.

       Renumber
              The RasMol renumber command sequentially numbers the residues  in  a  macromolecular  chain.   The
              optional  parameter  specifies  the  value  of the first residue in the sequence. By default, this
              value is one. For proteins, each amino acid is numbered consecutively from the N terminus to the C
              terminus.  For  nucleic  acids, each base is numbered from the 5' terminus to the 3' terminus. All
              chains in the current database are renumbered and gaps in the original sequence are  ignored.  The
              starting value for numbering may be negative.

       Reset  The  RasMol reset command restores the original viewing transformation and centre of rotation. The
              scale is set to its default value, zoom 100, the centre of rotation is set to the geometric centre
              of  the  currently  loaded  molecule,  centre  all, this centre is translated to the middle of the
              screen and the viewpoint set to the default orientation.

              This command should not be mistaken for the RasMol zap command which deletes the currently  stored
              molecule, returning the program to its initial state.

       Restrict
              The  RasMol  restrict  command  both  defines  the  currently  selected region of the molecule and
              disables the representation of (most of) those parts of the  molecule  no  longer  selected.   All
              subsequent  RasMol  commands  that  modify  a  molecule's colour or representation affect only the
              currently selected region. The parameter of a restrict command is a RasMol atom expression that is
              evaluated  for  every  atom  of  the  current molecule. This command is very similar to the RasMol
              select command, except restrict disables the wireframe, spacefill and backbone representations  in
              the non-selected region.

              Type  "help  expression"  for  more  information  on  RasMol  atom expressions or see section Atom
              Expressions.

       Ribbons
              The RasMol ribbons command displays the currently loaded protein or nucleic acid as a smooth solid
              "ribbon"  surface  passing  along  the  backbone of the protein.  The ribbon is drawn between each
              amino acid whose alpha carbon is currently selected. The colour of the ribbon is  changed  by  the
              RasMol  colour  ribbon  command. If the current ribbon colour is none (the default), the colour is
              taken from the alpha carbon at each position along its length.

              The width of the ribbon at each position is determined by the  optional  parameter  in  the  usual
              RasMol  units.  By  default  the  width of the ribbon is taken from the secondary structure of the
              protein or a constant value of 720 (2.88 Angstroms) for  nucleic  acids.   The  default  width  of
              protein  alpha  helices  and beta sheets is 380 (1.52 Angstroms) and 100 (0.4 Angstroms) for turns
              and random coil. The secondary structure assignment is either from  the  PDB  file  or  calculated
              using  the  DSSP algorithm as used by the structure command. This command is similar to the RasMol
              command strands which renders the biomolecular ribbon as parallel depth-cued curves.

       Rotate Rotate the molecule about the specified axis.  Permitted values for the axis  parameter  are  "x",
              "y",  "z"  and  "bond".  The integer parameter states the angle in degrees for the structure to be
              rotated. For the X and Y axes, positive values move the closest point up and right,  and  negative
              values move it down and left, respectively. For the Z axis, a positive rotation acts clockwise and
              a negative angle anti-clockwise.

              Alternatively, this command may be used to  specify  which  rotations  the  mouse  or  dials  will
              control.   If rotate bond true is selected, the horizontal scroll bar will control rotation around
              the axis selected by the bond src dst pick command.  If rotate all true is selected, and  multiple
              molecules  have  been  loaded,  then  all molecules will rotate together.  In all other cases, the
              mouseand dials control the the rotation of the molecule selected by the molecule n command.

       Russian
              The RasMol Russian command sets the menus and messages to the Russian versions.

              This command may not work correctly unless appropriate fonts have been  installed.   The  commands
              Bulgarian, Chinese, English, French, Italian, Russian and Spanish may be used to select Bulgarian,
              Chinese, English, French, Italian, Japanese,  Russian  and  Spanish  menus  and  messages  if  the
              appropriate fonts have been installed.

       Save   Save  the  currently  selected  set of atoms in a Protein Data Bank (PDB), MDL, Alchemy(tm) or XYZ
              format file.  The distinction between this command and the RasMol write command has been  dropped.
              The  only  difference is that without a format specifier the save command generates a PDB file and
              the write command generates a GIF image.

       Script The RasMol script command reads a set of  RasMol  commands  sequentially  from  a  text  file  and
              executes  them.  This  allows  sequences  of  commonly used commands to be stored and performed by
              single command. A RasMol script file may contain a further script command up to a maximum  "depth"
              of  10,  allowing  complicated  sequences of actions to be executed. RasMol ignores all characters
              after the first '#' character on each line allowing the scripts to be annotated. Script files  are
              often also annotated using the RasMol echo command.

              The  most  common  way to generate a RasMol script file is to use the write script or write rasmol
              commands to output the sequence of commands that  are  needed  to  regenerate  the  current  view,
              representation and colouring of the currently displayed molecule.

              The RasMol command source is synonymous with the script command.

       Select Define  the  currently  selected  region  of  the  molecule.  All  subsequent RasMol commands that
              manipulate a molecule or modify its colour or representation only affect  the  currently  selected
              region.  The parameter of a select command is a RasMol expression that is evaluated for every atom
              of the current molecule. The currently selected (active) region of the molecule  are  those  atoms
              that  cause  the  expression to evaluate true. To select the whole molecule use the RasMol command
              select all.  The behaviour of the select command without  any  parameters  is  determined  by  the
              RasMol hetero and hydrogen parameters.

              Type  "help  expression"  for  more  information  on  RasMol  atom expressions or see section Atom
              Expressions.

       Set    The RasMol set command allows the user to alter various internal program parameters such as  those
              controlling  rendering  options.  Each parameter has its own set or permissible parameter options.
              Typically, omitting the parameter option resets that parameter to its default  value.  A  list  of
              valid parameter names is given below.

       Show   The  RasMol  show  command  display  details  of  the status of the currently loaded molecule. The
              command show information lists the molecule's name, classification, PDB code  and  the  number  of
              atoms, chains, groups it contains.  If hydrogen bonding, disulphide bridges or secondary structure
              have been determined, the  number  of  hbonds,  ssbonds,  helices,  ladders  and  turns  are  also
              displayed,  respectively.  The command show centre shows any non-zero centering values selected by
              the centre [CenX, CenY, CenZ] command. The command show phipsi shows the phi and psi angles of the
              currently  selected  residues and the omega angles of cis peptide bonds. The command show RamPrint
              (or 'show RPP' or 'show RamachandranPrinterPlot') shows a simple Ramachandran printer plot in  the
              style  of  Frances  Bernstein's fisipl program.  The command show rotation (or 'show rot' or 'show
              'rotate') shows the currently selected values of z, y, x and bond rotations, if any.  The  command
              show  selected (or 'show selected group' or 'show selected chain' or  'show selected atom' ) shows
              the groups (default), chains or atoms of the current selection.  The command show  sequence  lists
              the  residues that comprise each chain of the molecule.  The command show symmetry shows the space
              group and unit cell of the molecule. The command show translation shows any  non-zero  translation
              values  selected by the translate <axis> <value> command. The command show zoom shows any non-zero
              zoom value selected by the zoom <value> command.

       Slab   The RasMol slab command enables, disables or positions the z-clipping plane of the  molecule.  The
              program  only  draws  those  portions  of  the  molecule that are further from the viewer than the
              slabbing plane.  Integer values range from zero at the very back of the molecule to 100  which  is
              completely  in front of the molecule. Intermediate values determine the percentage of the molecule
              to be drawn.

              This command interacts with the depth <value> command, which clips to  the  rear  of  a  given  z-
              clipping plane.

       Spacefill
              The  RasMol  spacefill  command  is used to represent all of the currently selected atoms as solid
              spheres. This command is used to produce both union-of-spheres  and  ball-and-stick  models  of  a
              molecule.  The  command,  spacefill true, the default, represents each atom as a sphere of van der
              Waals radius.  The command spacefill off turns off the representation  of  the  selected  atom  as
              spheres.  A  sphere  radius may be specified as an integer in RasMol units (1/250th Angstrom) or a
              value containing a decimal point. A  value  of  500  (2.0  Angstroms)  or  greater  results  in  a
              "Parameter value too large" error.

              The  temperature  option  sets  the  radius  of each sphere to the value stored in its temperature
              field. Zero or negative values have no effect and values greater than 2.0 are  truncated  to  2.0.
              The  user  option  allows  the  radius  of  each sphere to be specified by additional lines in the
              molecule's PDB file using Raster 3D's COLOUR record extension.

              The RasMol command cpk is synonymous with the spacefill command.

              The RasMol command cpknew is synonymous  with  the  spacefill  command,  except  that  a  slightly
              different set of colours is used.

       Spanish
              The RasMol Spanish command sets the menus and messages to the Spanish versions.

              This  command  may  not work correctly unless appropriate fonts have been installed.  The commands
              Bulgarian, Chinese, English, French, Italian, Russian and Spanish may be used to select Bulgarian,
              Chinese,  English,  French,  Italian,  Japanese,  Russian  and  Spanish  menus and messages if the
              appropriate fonts have been installed.

       SSBonds
              The RasMol ssbonds command is used to represent the disulphide bridges of the protein molecule  as
              either  dotted lines or cylinders between the connected cysteines. The first time that the ssbonds
              command is used, the program searches the structure of the protein  to  find  half-cysteine  pairs
              (cysteines  whose sulphurs are within 3 Angstroms of each other) and reports the number of bridges
              to the user. The command ssbonds on displays the selected "bonds" as dotted lines, and the command
              ssbonds  off  disables  the  display  of  ssbonds  in  the  currently  selected area. Selection of
              disulphide bridges is identical to normal bonds, and may be adjusted using the RasMol set bondmode
              command.  The  colour  of  disulphide  bonds  may  be changed using the colour ssbonds command. By
              default, each disulphide bond has the colours of its connected atoms.

              By default disulphide bonds are drawn between the sulphur atoms within  the  cysteine  groups.  By
              using the set ssbonds command the position of the cysteine's alpha carbons may be used instead.

       Star   The  RasMol  star  command  is used to represent all of the currently selected atoms as stars (six
              strokes, one each in the x, -x, y, -y, z and -z  directions).   The  commands  select  not  bonded
              followed  by  star  75 are useful to mark unbonded atoms in a wireframe display with less overhead
              than provided by spacefill 75.  This can  be  done  automatically  for  all  subsequent  wireframe
              displays with the command set bondmode not bonded.

              The  command  star  true, the default, represents each atom as a star with strokes length equal to
              van der Waals radius.  The command star off turns off the representation of the selected  atom  as
              stars. A star stroke length may be specified as an integer in RasMol units (1/250th Angstrom) or a
              value containing a decimal point. A  value  of  500  (2.0  Angstroms)  or  greater  results  in  a
              "Parameter value too large" error.

              The  temperature option sets the stroke length of each star to the value stored in its temperature
              field. Zero or negative values have no effect and values greater than 2.0 are  truncated  to  2.0.
              The  user  option allows the stroke length of each star to be specified by additional lines in the
              molecule's PDB file using Raster 3D's COLOUR record extension.

              The RasMol spacefill command can be used for more artistic rendering of atoms as spheres.

       Stereo The RasMol stereo command provides side-by-side stereo display of  images.  Stereo  viewing  of  a
              molecule may be turned on (and off) either by selecting Stereo from the Options menu, or by typing
              the commands stereo on or stereo off.

              Starting with RasMol version 2.7.2.1, the Stereo menu selection and  the  command  stereo  without
              arguments  cycle from the initial state of stereo off to stereo on in cross-eyed mode to stereo on
              in wall-eyed mode and then back to stereo off.

              The separation angle between the two views may be  adjusted  with  the  set  stereo  [-]  <number>
              command, where positive values result in crossed eye viewing and negative values in relaxed (wall-
              eyed) viewing.  The inclusion of [-] <number> in the stereo command, as for example in stereo 3 or
              stereo -5, also controls angle and direction.

              The  stereo  command  is  only  partially  implemented. When stereo is turned on, the image is not
              properly recentred. (This can be done with a translate x -<number>
               command.)  It is not supported in vector PostScript output files,  is  not  saved  by  the  write
              script  command,  and in general is not yet properly interfaced with several other features of the
              program.

       Strands
              The RasMol strands command displays the currently loaded protein  or  nucleic  acid  as  a  smooth
              "ribbon" of depth-cued curves passing along the backbone of the protein. The ribbon is composed of
              a number of strands that run parallel to one another along the peptide plane of each residue.  The
              ribbon  is  drawn between each amino acid whose alpha carbon is currently selected.  The colour of
              the ribbon is changed by the RasMol colour ribbon command. If the current ribbon  colour  is  none
              (the  default),  the  colour is taken from the alpha carbon at each position along its length. The
              central and outermost strands may be coloured independently using the colour  ribbon1  and  colour
              ribbon2  commands,  respectively.  The  number  of  strands in the ribbon may be altered using the
              RasMol set strands command.

              The width of the ribbon at each position is determined by the  optional  parameter  in  the  usual
              RasMol  units.  By  default  the  width of the ribbon is taken from the secondary structure of the
              protein or a constant value of 720 for nucleic acids  (which  produces  a  ribbon  2.88  Angstroms
              wide).  The default width of protein alpha helices and beta sheets is 380 (1.52 Angstroms) and 100
              (0.4 Angstroms) for turns and random coil. The secondary structure assignment is either  from  the
              PDB  file or calculated using the DSSP algorithm as used by the structure command. This command is
              similar to the RasMol command ribbons which renders the biomolecular ribbon  as  a  smooth  shaded
              surface.

       Structure
              The  RasMol  structure command calculates secondary structure assignments for the currently loaded
              protein. If the original PDB file contained structural assignment records (HELIX, SHEET and  TURN)
              these  are  discarded.   Initially,  the hydrogen bonds of the current molecule are found, if this
              hasn't been done already. The secondary structure is then determined  using  Kabsch  and  Sander's
              DSSP algorithm. Once finished the program reports the number of helices, strands and turns found.

       Surface
              The RasMol surface command renders a Lee-Richards molecular surface resulting from rolling a probe
              atom on the selected atoms.  The value given specifies the radius of the probe.  If given  in  the
              first  form,  the evolute of the surface of the probe is shown (the solvent excluded surface).  If
              given in the second form, the envelope of the positions of the center of the probe is  shown  (the
              solvent accessible surface).

       Trace  The  RasMol  trace  command  displays a smooth spline between  consecutive alpha carbon positions.
              This spline does not pass exactly through the alpha carbon position of each residue, but   follows
              the  same  path as ribbons, strands and cartoons.  Note that residues may be displayed as ribbons,
              strands, cartoons or as a trace.  Enabling one  of  these  representations  disables  the  others.
              However,  a  residue  may  be  displayed  simultaneously  as  backbone  and  as  one  of the above
              representations.  This may change in future versions of RasMol.  Prior to version 2.6,  trace  was
              synonymous with backbone.

              Trace  temperature  displays  the  backbone  as  a  wider cylinder at high temperature factors and
              thinner  at  lower.   This  representation  is  useful  to   X-ray   crystallographers   and   NMR
              spectroscopists.

       Translate
              The  RasMol  translate command moves the position of the centre of the molecule on the screen. The
              axis parameter specifies along which axis the molecule is to be moved and  the  integer  parameter
              specifies  the  absolute position of the molecule centre from the middle of the screen.  Permitted
              values for the axis parameter are "x", "y" and "z".  Displacement values must be between -100  and
              100  which  correspond  to  moving  the  current  molecule  just  off  the  screen. A positive "x"
              displacement moves the molecule to the right, and a positive "y" displacement moves  the  molecule
              down  the screen. The pair of commands translate x 0 and translate y 0 centres the molecule on the
              screen.

       UnBond The RasMol command unbond <number> <number> removes the designated bond from the drawing.

              The command unbond without arguments removes  a  bond  previously  picked  by  the  bond  <number>
              <number> pick command.

       Wireframe
              The  RasMol wireframe command represents each bond within the selected region of the molecule as a
              cylinder, a line or a depth-cued vector. The display of bonds as depth-cued vectors (drawn  darker
              the  further  away  from  the  viewer) is turned on by the command wireframe or wireframe on.  The
              selected bonds are displayed as cylinders by specifying a radius either as an  integer  in  RasMol
              units  or  containing  a  decimal  point  as  a value in Angstroms.  A parameter value of 500 (2.0
              Angstroms) or above results in an "Parameter value too large" error. Bonds may be  coloured  using
              the colour bonds command.

              If  the  selected  bonds involved atoms of alternate conformers then the bonds are narrowed in the
              middle to a radius of .8 of the specified radius (or to  the  radius  specified  as  the  optional
              second parameter).

              Non-bonded atoms, which could become invisible in an ordinary wireframe display can be marked by a
              preceding set bondmode not bonded command.  If nearly co-linear bonds to atoms cause  them  to  be
              difficult  to  see  in  a wireframe display, the set bondmode all command will add markers for all
              atoms in subsequent wireframe command executions.

       Write  Write the current image to a file in a standard format. Currently  supported  image  file  formats
              include  bmp  (Microsoft bitmap) and gif (Compuserve GIF), iris (IRIS RGB), ppm (Portable Pixmap),
              ras (Sun rasterfile), ps and  epsf  (Encapsulated  PostScript),  monops  (Monochrome  Encapsulated
              PostScript), pict (Apple PICT), vectps (Vector Postscript).  The write command may also be used to
              generate command scripts for other  graphics  programs.  The  format  script  writes  out  a  file
              containing  the RasMol script commands to reproduce the current image. The format molscript writes
              out the commands required to render the current view of the molecule as ribbons  in  Per  Kraulis'
              Molscript  program  and the format kinemage the commands for David Richardson's program Mage.  The
              following formats are useful for further processing: povray (POVRay 2), povray3 (POVRay 3 -- under
              development), vrml (VRML file).  Finally, several formats are provided to provide phi-psi data for
              listing or for phipsi (phi-psi data as an annotated list with cis omegas), ramachan  and  RDF  and
              RamachandranDataFile   (phi-psi   data   as   columns   of   numbers   for   gnuplot),   RPP   and
              RamachandranPrinterPlot (phi-psi data as a printer plot).

              The distinction between this command and the RasMol  save  command  has  been  dropped.  The  only
              difference  is that without a format specifier the save command generates a PDB file and the write
              command generates a GIF image.

       Zap    Deletes the contents of the current database and  resets  parameter  variables  to  their  initial
              default state.

       Zoom   Change  the  magnification  of the currently displayed image. Boolean parameters either magnify or
              reset the scale of current molecule. An integer parameter specifies the desired magnification as a
              percentage of the default scale. The minimum parameter value is 10; the maximum parameter value is
              dependent upon the size of the molecule being displayed. For medium sized proteins this  is  about
              500.

SET PARAMETERS

       RasMol  has  a number of internal parameters that may be modified using the set command. These parameters
       control a number of program options such as rendering options and mouse button mappings.

           picking         play.fps        radius          record.aps

       Set Ambient
              The RasMol ambient parameter is used to control the amount of ambient (or  surrounding)  light  in
              the  scene.  The  ambient value must be between 0 and 100. It controls the percentage intensity of
              the darkest shade of an object. For a solid object, this is the intensity of surfaces facing  away
              from  the  light  source  or  in  shadow.  For depth-cued objects this is the intensity of objects
              furthest from the viewer.

              This  parameter  is  commonly  used  to  correct  for  monitors  with  different  "gamma   values"
              (brightness),  to  change  how light or dark a hardcopy image appears when printed or to alter the
              feeling of depth for wireframe or ribbon representations.

       Set Axes
              The RasMol axes parameter controls the display  of  orthogonal  coordinate  axes  on  the  current
              display.  The  coordinate  axes  are  those  used in the molecule data file, and the origin is the
              centre of the molecule's bounding box. The set  axes  command  is  similar  to  the  commands  set
              boundbox  and  set  unitcell  that  display  the  bounding box and the crystallographic unit cell,
              respectively.

       Set Backfade
              The RasMol backfade parameter is used to control backfade  to  the  specified  background  colour,
              rather  than black.  This is controlled by the commands set backfade on and set backfade off.  For
              example, this may be used to generate depth-cued images that fade to white, rather than black.

       Set Background
              The RasMol background parameter is used to set the colour of the "canvas" background.  The  colour
              may  be  given  as  either  a  colour  name  or a comma separated triple of Red, Green, Blue (RGB)
              components enclosed in square brackets. Typing the command help colours will give a  list  of  the
              predefined  colour  names  recognised  by  RasMol.   When  running  under  X  Windows, RasMol also
              recognises colours in the X server's colour name database.

              The command set background is synonymous with the RasMol command background.

       Set BondMode
              The RasMol set bondmode command controls  the  mechanism  used  to  select  individual  bonds  and
              modifies the display of bonded and non-bonded atoms by subsequent wireframe commands.

              When  using  the select and restrict commands, a given bond will be selected if i) the bondmode is
              or and either of the connected atoms is selected, or ii)  the  bondmode  is  and  and  both  atoms
              connected  by  the bond are selected. Hence an individual bond may be uniquely identified by using
              the command set bondmode and and then uniquely selecting the atoms at both ends.

              The bondmode [all | none | not bonded] commands add star  75  or  spacefill  75  markers  for  the
              designated  atoms  to  wireframe  displays.  Stars are used when the specified wireframe radius is
              zero.

       Set Bonds
              The RasMol bonds parameter is used to control display of  double  and  triple  bonds  as  multiple
              lines  or  cylinders.   Currently bond orders are only read from  MDL Mol files, Sybyl Mol2 format
              files, Tripos Alchemy format files, CIF and mmCIF,  and suitable PDB files.  Double  (and  triple)
              bonds  are  specified  in  some   PDB files by specifying a given bond twice  (and three times) in
              CONECT records.  The  command set bonds on enables the display of bond orders,  and   the  command
              set bonds off disables them.

       Set BoundBox
              The  RasMol  boundbox parameter controls the display of the current molecule's bounding box on the
              display. The bounding box is orthogonal to the data  file's  original  coordinate  axes.  The  set
              boundbox  command  is  similar  to  the commands set axes and set unitcell that display orthogonal
              coordinate axes and the bounding box, respectively.

       Set Cartoon
              The RasMol cartoon parameter is used to control display of the  cartoon  version  of  the  ribbons
              display.   By  default,  the  C-termini  of  beta-sheets are displayed as arrow heads. This may be
              enabled and disabled using the set cartoons <boolean> command. The depth of  the  cartoon  may  be
              adjusted  using  the  cartoons  <number>  command. The set cartoons command without any parameters
              returns these two options to
               their default values.

       Set CisAngle
              The RasMol cisangle parameter controls the cutoff angle for identifying cis peptide
               bonds.  If no value is given, the cutoff is set to 90 degrees.

       Set Display
              This command controls the display mode within RasMol.  By  default,  set  display  normal,  RasMol
              displays  the  molecule  in  the  representation  specified  by  the user. The command set display
              selected changes the display mode such that the molecule is temporarily drawn so  as  to  indicate
              currently  selected  portion  of the molecule. The user specified colour scheme and representation
              remains unchanged.  In this representation all selected atoms are shown  in  yellow  and  all  non
              selected  atoms  are shown in blue. The colour of the background is also changed to a dark grey to
              indicate the change of display mode.  This command is typically only used  by  external  Graphical
              User Interfaces (GUIs).

       Set FontSize
              The  RasMol  set  fontsize  command  is  used to control the size of the characters that form atom
              labels. This value corresponds to the height of the displayed character  in  pixels.  The  maximum
              value  of  fontsize  is  48 pixels, and the default value is 8 pixels high.  Fixed or proportional
              spacing may be selected by appending the "FS" or "PS" modifiers,  respectively.   The  default  is
              "FS".   To display atom labels on the screen use the RasMol label command and to change the colour
              of displayed labels, use the colour labels command.

       Set FontStroke
              The RasMol set fontstroke command is used  to  control  the  size  of  the  stroke  width  of  the
              characters  that  form  atom labels.  This value is the radius in pixels of cylinders used to form
              the strokes.  The special value of "0" is the default used for  the  normal  single  pixel  stroke
              width,  which allows for rapid drawing and rotation of the image.  Non-zero values are provided to
              allow for more artistic atom labels for publication at the expense of extra time in rendering  the
              image.

              When  wider  strokes  are  used,  a  larger  font size is recommend, e.g.  by using the RasMol set
              fontsize 24 PS command, followed by set fontstroke 2

              To display atom labels on the screen use the RasMol label command, and to  change  the  colour  of
              displayed labels use the colour labels command.

       Set HBonds
              The  RasMol  hbonds  parameter  determines  whether hydrogen bonds are drawn between the donor and
              acceptor atoms of the hydrogen bond, set hbonds sidechain or between the alpha carbon atoms of the
              protein  backbone  and  between  the  phosphorous  atoms  of the nucleic acid backbone, set hbonds
              backbone.  The actual display of hydrogen bonds is  controlled  by  the  hbonds  command.  Drawing
              hydrogen  bonds between protein alpha carbons or nucleic acid phosphorous atoms is useful when the
              rest of the molecule is shown in only a schematic representation  such  as  backbone,  ribbons  or
              strands.  This parameter is similar to the RasMol ssbonds parameter.

       Set Hetero
              The  RasMol  hetero  parameter  is  used  to  modify  the 'default' behaviour of the RasMol select
              command, i.e. the behaviour of select without any  parameters.  When  this  value  is  false,  the
              default select region does not include any heterogeneous atoms (refer to the predefined set hetero
              ). When this value is true, the default select region may contain hetero atoms. This parameter  is
              similar  to  the  RasMol  hydrogen  parameter  which  determines  whether hydrogen atoms should be
              included in the default set. If both hetero and hydrogen are true, select without  any  parameters
              is equivalent to select all.

       Set HourGlass
              The  RasMol  hourglass parameter allows the user to enable and disable the use of the 'hour glass'
              cursor used by RasMol to indicate that the program is currently busy drawing the next  frame.  The
              command  set  hourglass  on  enables  the indicator, whilst set hourglass off prevents RasMol from
              changing the cursor. This is useful when spinning the molecule, running  a  sequence  of  commands
              from  a  script file or using interprocess communication to execute complex sequences of commands.
              In these cases a 'flashing' cursor may be distracting.

       Set Hydrogen
              The RasMol hydrogen parameter is used to modify the  "default"  behaviour  of  the  RasMol  select
              command,  i.e.  the  behaviour  of  select  without  any parameters. When this value is false, the
              default select region does not include any hydrogen, deuterium or  tritium  atoms  (refer  to  the
              predefined set hydrogen ). When this value is true, the default select region may contain hydrogen
              atoms. This parameter  is  similar  to  the  RasMol  hetero  parameter  which  determines  whether
              heterogeneous  atoms  should be included in the default set. If both hydrogen and hetero are true,
              select without any parameters is equivalent to select all.

       Set Kinemage
              The RasMol set kinemage command controls the amount of detail stored in  a  Kinemage  output  file
              generated  by  the  RasMol  write  kinemage  command. The output kinemage files are intended to be
              displayed by David Richardson's Mage program.  set kinemage false, the default,  only  stores  the
              currently  displayed  representation  in the generated output file. The command set kinemage true,
              generates a more complex Kinemage that contains both the wireframe and backbone representations as
              well as the coordinate axes, bounding box and crystal unit cell.

       Set Menus
              The RasMol set menus command enables the canvas window's menu buttons or menu bar. This command is
              typically only used by graphical user interfaces or to create as large an image as  possible  when
              using Microsoft Windows.

       Set Monitor
              The  RasMol  set  monitor command enables monitors.  The distance monitor labels may be turned off
              with the command set monitor off, and re-enabled with the command set monitor on.

       Set Mouse
              The RasMol set mouse command sets the rotation, translation, scaling and zooming  mouse  bindings.
              The  default  value  is  rasmol  which  is suitable for two button mice (for three button mice the
              second and third buttons are synonymous); X-Y rotation is controlled by the first button, and  X-Y
              translation  by  the  second. Additional functions are controlled by holding a modifier key on the
              keyboard.  [Shift] and the first button performs scaling, [shift] and the second  button  performs
              Z-rotation,  and [control] and the first mouse button controls the clipping plane. The insight and
              quanta options provide the same mouse bindings as other packages for experienced users.

       Set Picking
              The RasMol set picking series of commands  affects  how  a  user  may  interact  with  a  molecule
              displayed on the screen in RasMol.

              Enabling/Disabling  Atom  Identification  Picking:  Clicking  on an atom with the mouse results in
              identification and the display of its residue name, residue number, atom name, atom serial  number
              and  chain  in the command window. This behavior may be disabled with the command set picking none
              and restored with the command set picking ident.  The command set picking coord  adds  the  atomic
              coordinates of the atom to the display.

              Disabling  picking,  by using set picking off is useful when executing the pause command in RasMol
              scripts as it prevents the display of spurious message on the command line  while  the  script  is
              suspended.

              Measuring  Distances,  Angles  and  Torsions:  Interactive  measurement  of  distances, angles and
              torsions is achieved using the commands: set picking distance, set picking  monitor,  set  picking
              angle  and  set  picking  torsion, respectively. In these modes, clicking on an atom results in it
              being identified on the rasmol command line. In addition every atom  picked  increments  a  modulo
              counter  such that in distance mode, every second atom displays the distance (or distance monitor)
              between this atom and the previous one. In angle mode, every third atom displays the angle between
              the  previous  three  atoms and in torsion mode every fourth atom displays the torsion between the
              last four atoms. By holding down the shift key while picking an atom, this modulo counter  is  not
              incremented  and  allows,  for example, the distances of consecutive atoms from a fixed atom to be
              displayed. See the monitor command for how to control the display of distance  monitor  lines  and
              labels.

              Labelling  Atoms with the Mouse: The mouse may also be used to toggle the display of an atom label
              on a given atom. The RasMol command set picking label removes a label from a  picked  atom  if  it
              already has one or displays a concise label at that atom position otherwise.

              Centring Rotation with the Mouse: A molecule may be centred on a specified atom position using the
              RasMol commands set picking centre or set picking center.  In this mode, picking  an  atom  causes
              all futher rotations to be about that point.

              Picking  a  Bond as a Rotation Axis: Any bond may be picked as an axis of rotation for the portion
              of the molecule beyond the second atom selected.  This feature should be used with caution, since,
              naturally, it changes the conformation of the molecule.  After executing set picking bond or using
              the equivalent "Pick Bond" in the "Settings" menu, a bond to be rotated is picked  with  the  same
              sort  of  mouse  clicks  as  are used for picking atoms for a distance measurement.  Normally this
              should be done where a bond exists, but if no bond exists, it will be added.  The bond  cannot  be
              used  for  rotation  if  it  is  part  of a ring of any size.  All bonds selected for rotation are
              remembered so that they can be properly reported when writing a script, but only the most recently
              selected bond may be actively rotated.

              Enabling  Atom/Group/Chain Selection Picking: Atoms, groups and chains may be selected (as if with
              the select command), with the set picking atom, set picking group,  set  picking  chain  commands.
              For  each  of  these commands, the shift key may be used to have a new selection added to the old,
              and the control key may be used to have a new selection deleted from the old. When the set picking
              atom  command  is given, the mouse can be used to pick or to drag a box around the atoms for which
              selection is desired.  When the set picking group command is given, picking any an atom will cause
              selection  of  all  atoms which agree in residue number with the picked atom, even if in different
              chains.  When the set picking chain command is given, picking any atom will cause selection of all
              atoms which agree in chain identifier with the picked atom.

       Set Play
              The  RasMol  set  play.fps  command gives the number of frames per second for playback by the play
              command (default 24 frames per second).

              In the current release of RasMol, the play timing is not controlled by this parameter.

       Set Radius
              The RasMol set radius command is used to alter the behaviour of the RasMol dots command  depending
              upon  the  value  of  the  solvent parameter.  When solvent is true, the radius parameter controls
              whether a true van der Waals' surface is generated by the dots command. If the value of radius  is
              anything  other  than  zero, that value is used as the radius of each atom instead of its true vdW
              value. When the value of solvent is true, this parameter determines the 'probe  sphere'  (solvent)
              radius.  The parameter may be given as an integer in rasmol units or containing a decimal point in
              Angstroms. The default value of this parameter is determined by the value of solvent and  changing
              solvent resets radius to its new default value.

       Set Record
              The  RasMol  set  record.aps  gives  the  maximum  on-screen  velocity  in Angstroms per second in
              animating translations, rotations and zooms (default 10 A/second).

              The RasMol set record.aps command gives number of frames per second for recording  by  the  record
              command (default 24 frames per second).

              The  RasMol  set  record.dwell command sets the time in seconds to dwell on a change in appearance
              (default .5 sec).

       Set ShadePower
              The shadepower parameter (adopted from RasTop) determines the  shade  repartition  (the  contrast)
              used in rendering solid objects. This value between 0 and 100 adjusts shading on an object surface
              oriented along the direction to the light source.  Changing  the  shadepower  parameter  does  not
              change  the maximum or the minimum values of this shading, as does changing the ambient parameter.
              A value of 100 concentrates the light on the top of spheres,  giving  a  highly  specular,  glassy
              rendering (see the specpower parameter).  A value of 0 distributes the light on the entire object.

              This implementation of shadepower differs from the one in RasTop only in the choice of range (0 to
              100 versus -20 to 20 in RasTop).

       Set Shadow
              The RasMol set shadow command enables and disables ray-tracing of the  currently  rendered  image.
              Currently only the spacefilling representation is shadowed or can cast shadows. Enabling shadowing
              will automatically disable the Z-clipping (slabbing) plane  using  the  command  slab  off.   Ray-
              tracing  typically  takes about several seconds for a moderately sized protein.  It is recommended
              that shadowing be normally disabled whilst the molecule is being transformed or  manipulated,  and
              only enabled once an appropriate viewpoint is selected, to provide a greater impression of depth.

       Set SlabMode
              The  RasMol  slabmode  parameter  controls the rendering method of objects cut by the slabbing (z-
              clipping) plane. Valid slabmode parameters are "reject", "half", "hollow", "solid" and "section".

       Set Solvent
              The RasMol set solvent command is used to control  the  behaviour  of  the  RasMol  dots  command.
              Depending  upon  the  value  of the solvent parameter, the dots command either generates a van der
              Waals' or a solvent accessible surface around the currently selected set of atoms.  Changing  this
              parameter  automatically resets the value of the RasMol radius parameter.  The command set solvent
              false, the default value, indicates that a van der Waals' surface should be generated  and  resets
              the  value  of  radius  to  zero.  The  command  set  solvent  true indicates that a 'Connolly' or
              'Richards' solvent accessible surface should be drawn and sets the radius parameter,  the  solvent
              radius, to 1.2 Angstroms (or 300 RasMol units).

       Set Specular
              The  RasMol  set specular command enables and disables the display of specular highlights on solid
              objects drawn by RasMol. Specular highlights appear as white reflections of the  light  source  on
              the  surface  of  the  object. The current RasMol implementation uses an approximation function to
              generate this highlight.

              The specular highlights on the surfaces of solid objects may be  altered  by  using  the  specular
              reflection coefficient, which is altered using the RasMol set specpower command.

       Set SpecPower
              The  specpower  parameter determines the shininess of solid objects rendered by RasMol. This value
              between 0 and 100 adjusts the reflection coefficient used in specular highlight calculations.  The
              specular  highlights are enabled and disabled by the RasMol set specular command. Values around 20
              or 30 produce plastic looking surfaces.  High values represent more shiny surfaces such as metals,
              while lower values produce more diffuse/dull surfaces.

       Set SSBonds
              The  RasMol  ssbonds parameter determines whether disulphide bridges are drawn between the sulphur
              atoms in the sidechain (the default) or between the alpha carbon atoms  in  the  backbone  of  the
              cysteines residues. The actual display of disulphide bridges is controlled by the ssbonds command.
              Drawing disulphide bridges between alpha carbons is useful when the rest of the protein  is  shown
              in  only  a  schematic  representation  such  as  backbone, ribbons or strands.  This parameter is
              similar to the RasMol hbonds parameter.

       Set Stereo
              The RasMol set stereo parameter controls the separation between the left and right images. Turning
              stereo on and off doesn't reposition the centre of the molecule.

              Stereo  viewing  of  a  molecule  may  be  turned on (and off) either by selecting Stereo from the
              Options menu, or by typing the commands stereo on or stereo off.

              The separation angle between the two views may be  adjusted  with  the  set  stereo  [-]  <number>
              command, where positive values result in crossed eye viewing and negative values in relaxed (wall-
              eyed) viewing. Currently, stereo viewing is not supported in vector PostScript output files.

       Set Strands
              The RasMol strands parameter controls the number of parallel strands that  are  displayed  in  the
              ribbon  representations  of  proteins. The permissible values for this parameter are 1, 2, 3, 4, 5
              and 9. The default value is 5. The number of strands is constant for all ribbons being  displayed.
              However,  the  ribbon  width  (the  separation  between strands) may be controlled on a residue by
              residue basis using the RasMol ribbons command.

       Set Transparent
              The RasMol transparent parameter controls the  writing  of  transparent  GIFs  by  the  write  gif
              <filename>  command.   This  may  be  controlled by the set transparent on and set transparent off
              commands.

       Set UnitCell
              The RasMol unitcell parameter controls the display  of  the  crystallographic  unit  cell  on  the
              current  display. The crystal cell is only enabled if the appropriate crystal symmetry information
              is contained in the PDB, CIF or mmCIF data file. The RasMol command show symmetry display  details
              of  the  crystal's  space  group  and  unit  cell axes. The set unitcell command is similar to the
              commands set axes and set boundbox that display orthogonal coordinate axes and the  bounding  box,
              respectively.

       Set VectPS
              The  RasMol vectps parameter is use to control the way in which the RasMol write command generates
              vector PostScript output files. The command set vectps on enables the use of black outlines around
              spheres  and  cylinder bonds producing "cartoon-like" high resolution output. However, the current
              implementation of RasMol incorrectly cartoons spheres that are intersected by more than one  other
              sphere.  Hence  "ball  and stick" models are rendered correctly but not large spacefilling spheres
              models. Cartoon outlines can be disabled, the default, by the command set vectps off.

       Set Write
              The RasMol write parameter controls the use of the save and write commands within scripts, but  it
              may  only  be  executed  from  the command line.  By default, this value is false, prohibiting the
              generation of files in any scripts executed at  start-up  (such  as  those  launched  from  a  WWW
              browser). However, animators may start up RasMol interactively: type set write on and then execute
              a script to generate each frame using the source command.

ATOM EXPRESSIONS

       RasMol atom expressions uniquely identify an arbitrary group of atoms within a molecule. Atom expressions
       are  composed of either primitive expressions, predefined sets, comparison operators, within expressions,
       or logical (boolean) combinations of the above expression types.

       The logical operators allow complex queries to be constructed out of  simpler  ones  using  the  standard
       boolean  connectives  and,  or  and  not.   These  may  be  abbreviated  by the symbols "&", "|" and "!",
       respectively. Parentheses (brackets)  may  be  used  to  alter  the  precedence  of  the  operators.  For
       convenience, a comma may also be used for boolean disjunction.

       The  atom  expression  is  evaluated  for  each atom, hence protein and backbone selects protein backbone
       atoms, not the protein and [nucleic] acid backbone atoms!

       Primitive Expressions
              RasMol primitive expressions are the fundamental building blocks of atom  expressions.  There  are
              two  types  of primitive expression.  The first type is used to identify a given residue number or
              range of residue numbers. A single residue is identified by its number (position in the sequence),
              and  a  range  is specified by lower and upper bounds separated by a hyphen character. For example
              select 5,6,7,8 is also select 5-8.  Note that this  selects  the  given  residue  numbers  in  all
              macromolecule chains.

              The second type of primitive expression specifies a sequence of fields that must match for a given
              atom. The first part specifies a residue (or group  of  residues)  and  an  optional  second  part
              specifies  the  atoms within those residues. The first part consists of a residue name, optionally
              followed by a residue number and/or chain identifier.

              The second part consists of a period character followed by an atom name.  An atom name may  be  up
              to  four  alphabetic  or  numeric  characters.   An  optional  semicolon  followed by an alternate
              conformation identifier may be appended.  An optional slash followed by a model number may also be
              appended.

              An asterisk may be used as a wild card for a whole field and a question mark as a single character
              wildcard.

       Comparison Operators
              Parts of a molecule may also be distinguished using equality, inequality and ordering operators on
              their  properties.  The  format  of  such  comparison expression is a property name, followed by a
              comparison operator and then an integer value.

              The atom properties that may be used in RasMol are atomno for the atom serial number,  elemno  for
              the  atom's atomic number (element), resno for the residue number, radius for the spacefill radius
              in RasMol units (or zero if not represented as a sphere) and temperature  for  the  PDB  isotropic
              temperature value.

              The equality operator is denoted either "=" or "==".  The inequality operator as either "<>", "!="
              or "/=".  The ordering operators are "<" for less than, "<=" for less than or equal  to,  ">"  for
              greater than, and ">" for greater than or equal to.

       Within Expressions
              A RasMol within expression allows atoms to be selected on their proximity to another set of atoms.
              A within expression takes two parameters separated by a comma and surrounded by  parentheses.  The
              first  argument is an integer value called the "cut-off" distance of the within expression and the
              second argument is any  valid atom expression. The cut-off distance is expressed in either integer
              RasMol  units  or  Angstroms  containing a decimal point.  An atom is selected if it is within the
              cut-off distance of any of  the  atoms  defined  by  the  second  argument.  This  allows  complex
              expressions to be constructed containing nested within expressions.

              For example, the command select within(3.2,backbone) selects any atom within a 3.2 Angstrom radius
              of any atom in a protein or nucleic acid backbone.  Within expressions are particularly useful for
              selecting the atoms around an active site.

       Predefined Sets
              RasMol atom expressions may contain predefined sets. These sets are single keywords that represent
              portions of a molecule of interest.  Predefined sets are often  abbreviations  of  primitive  atom
              expressions.   In  some  cases  the use of predefined sets allows selection of areas of a molecule
              that could not otherwise be distinguished.  A list of  the  currently  predefined  sets  is  given
              below.   In addition to the sets listed here, RasMol also treats element names (and their plurals)
              as predefined sets containing all atoms of that element type, i.e. the command  select  oxygen  is
              equivalent to the command select elemno=8.

Predefined Sets

       AT Set This  set  contains  the  atoms in the complementary nucleotides adenosine and thymidine (A and T,
              respectively). All nucleotides are classified as either the set at or  the  set  cg  This  set  is
              equivalent to the RasMol atom expressions a,t, and nucleic and not cg.

       Acidic Set
              The  set  of  acidic  amino  acids.  These are the residue types Asp and Glu.  All amino acids are
              classified as either acidic, basic or  neutral.   This  set  is  equivalent  to  the  RasMol  atom
              expressions asp, glu and amino and not (basic or neutral).

       Acyclic Set
              The  set of atoms in amino acids not containing a cycle or ring. All amino acids are classified as
              either cyclic or acyclic.  This set is equivalent to the RasMol  atom  expression  amino  and  not
              cyclic.

       Aliphatic Set
              This  set  contains  the  aliphatic amino acids.  These are the amino acids Ala, Gly, Ile, Leu and
              Val.  This set is equivalent to the RasMol atom expression ala, gly, ile, leu, val.

       Alpha Set
              The set of alpha carbons in the protein molecule. This set  is  approximately  equivalent  to  the
              RasMol  atom  expression  *.CA.  This command should not be confused with the predefined set helix
              which contains the atoms in the amino acids of the protein's alpha helices.

       Amino Set
              This set  contains  all  the  atoms  contained  in  amino  acid  residues.   This  is  useful  for
              distinguishing  the  protein from the nucleic acid and heterogeneous atoms in the current molecule
              database.

       Aromatic Set
              The set of atoms in amino acids containing aromatic rings.  These are the amino  acids  His,  Phe,
              Trp  and  Tyr.   Because  they  contain  aromatic  rings all members of this set are member of the
              predefined set cyclic.  This set is equivalent to the RasMol atom expressions his, phe,  trp,  tyr
              and cyclic and not pro.

       Backbone Set
              This  set contains the four atoms of each amino acid that form the polypeptide N-C-C-O backbone of
              proteins, and the atoms of the  sugar  phosphate  backbone  of  nucleic  acids.   Use  the  RasMol
              predefined  sets  protein  and nucleic to distinguish between the two forms of backbone.  Atoms in
              nucleic acids and proteins are either backbone or sidechain.  This set is equivalent to the RasMol
              expression (protein or nucleic) and not sidechain.

              The predefined set mainchain is synonymous with the set backbone.

       Basic Set
              The  set of basic amino acids.  These are the residue types Arg, His and Lys.  All amino acids are
              classified as either acidic, basic or  neutral.   This  set  is  equivalent  to  the  RasMol  atom
              expressions arg, his, lys and amino and not (acidic or neutral).

       Bonded Set
              This  set  contain  all the atoms in the current molecule database that are bonded to at least one
              other atom.

       Buried Set
              This set contains the atoms in those amino acids that tend (prefer) to be buried  inside  protein,
              away  from  contact  with solvent molecules. This set refers to the amino acids preference and not
              the actual solvent accessibility for the current protein.   All  amino  acids  are  classified  as
              either  surface  or  buried.   This  set is equivalent to the RasMol atom expression amino and not
              surface.

       CG Set This set contains the atoms in the complementary nucleotides cytidine  and  guanosine  (C  and  G,
              respectively).  All  nucleotides  are  classified  as  either the set at or the set cg This set is
              equivalent to the RasMol atom expressions c,g and nucleic and not at.

       Charged Set
              This set contains the charged amino acids. These are the amino acids that  are  either  acidic  or
              basic.   Amino acids are classified as being either charged or neutral.  This set is equivalent to
              the RasMol atom expressions acidic or basic and amino and not neutral.

       Cyclic Set
              The set of atoms in amino acids containing a cycle or rings.  All amino acids  are  classified  as
              either  cyclic  or acyclic.  This set consists of the amino acids His, Phe, Pro, Trp and Tyr.  The
              members of the predefined set aromatic are members of this set.  The only cyclic but  non-aromatic
              amino  acid is proline.  This set is equivalent to the RasMol atom expressions his, phe, pro, trp,
              tyr and aromatic or pro and amino and not acyclic.

       Cystine Set
              This set contains the atoms of cysteine residues that form part of a disulphide bridge, i.e.  half
              cystines.  RasMol  automatically  determines  disulphide  bridges,  if  neither the predefined set
              cystine nor the RasMol ssbonds command have been used since the molecule was loaded.  The  set  of
              free cysteines may be determined using the RasMol atom expression cys and not cystine.

       Helix Set
              This  set  contains  all atoms that form part of a protein alpha helix as determined by either the
              PDB file author or Kabsch and Sander's DSSP algorithm.  By  default,  RasMol  uses  the  secondary
              structure determination given in the PDB file if it exists.  Otherwise, it uses the DSSP algorithm
              as used by the RasMol structure command.

              This predefined set should not be confused with the predefined set alpha which contains the  alpha
              carbon atoms of a protein.

       Hetero Set
              This  set  contains  all the heterogeneous atoms in the molecule. These are the atoms described by
              HETATM entries in the PDB file. These typically contain water, cofactors and  other  solvents  and
              ligands.  All  hetero  atoms are classified as either ligand or solvent atoms. These heterogeneous
              solvent atoms are further classified as either water or ions.

       Hydrogen Set
              This predefined set contains all  the  hydrogen,  deuterium  and  tritium  atoms  of  the  current
              molecule. This predefined set is equivalent to the RasMol atom expression elemno=1.

       Hydrophobic Set
              This  set contains all the hydrophobic amino acids.  These are the amino acids Ala, Leu, Val, Ile,
              Pro, Phe, Met and Trp.  All amino acids are classified as either hydrophobic or polar.   This  set
              is  equivalent to the RasMol atom expressions ala, leu, val, ile, pro, phe, met, trp and amino and
              not polar.

       Ions Set
              This set contains all the heterogeneous phosphate and sulphate ions in the current  molecule  data
              file.  A  large  number  of  these  ions  are  sometimes  associated with protein and nucleic acid
              structures determined by X-ray crystallography. These atoms tend to clutter an image.  All  hetero
              atoms are classified as either ligand or solvent atoms. All solvent atoms are classified as either
              water or ions.

       Large Set
              All amino acids are classified as either small, medium or large.  This set is  equivalent  to  the
              RasMol atom expression amino and not (small or medium).

       Ligand Set
              This  set  contains  all  the heterogeneous cofactor and ligand moieties that are contained in the
              current molecule data file.  This set is defined to be all  hetero  atoms  that  are  not  solvent
              atoms. Hence this set is equivalent to the RasMol atom expression hetero and not solvent.

       Medium Set
              All  amino  acids  are classified as either small, medium or large.  This set is equivalent to the
              RasMol atom expression amino and not (large or small).

       Neutral Set
              The set of neutral amino acids.  All amino  acids  are  classified  as  either  acidic,  basic  or
              neutral.  This set is equivalent to the RasMol atom expression amino and not (acidic or basic).

       Nucleic Set
              The  set  of  all  atoms  in nucleic acids, which consists of the four nucleotide bases adenosine,
              cytidine, guanosine and thymidine (A, C, G and T, respectively). All neucleotides  are  classified
              as either purine or pyrimidine.  This set is equivalent to the RasMol atom expressions a,c,g,t and
              purine or pyrimidine.  The symbols for RNA nucleotides (U, +U, I, 1MA, 5MC, OMC,  1MG,  2MG,  M2G,
              7MG, OMG, YG, H2U, 5MU, and PSU) are also recognized as members of this set.

       Polar Set
              This  set contains the polar amino acids.  All amino acids are classified as either hydrophobic or
              polar.  This set is equivalent to the RasMol atom expression amino and not hydrophobic.

       Protein Set
              The set of all atoms in proteins. This consists of the RasMol  predefined  set  amino  and  common
              post-translation modifications.

       Purine Set
              The  set  of  purine  nucleotides.   These  are  the  bases  adenosine  and  guanosine  (A  and G,
              respectively).  All nucleotides are either purines or pyrimidines.  This set is equivalent to  the
              RasMol atom expressions a,g and nucleic and not pyrimidine.

       Pyrimidine Set
              The  set  of  pyrimidine  nucleotides.   These  are  the  bases  cytidine  and thymidine (C and T,
              respectively).  All nucleotides are either purines or pyrimidines.  This set is equivalent to  the
              RasMol atom expressions c,t and nucleic and not purine.

       Selected Set
              This set contains the set of atoms in the currently selected region. The currently selected region
              is defined by the preceding select or restrict command and not the atom expression containing  the
              selected keyword.

       Sheet Set
              This set contains all atoms that form part of a protein beta sheet as determined by either the PDB
              file author or Kabsch and Sander's DSSP algorithm. By default, RasMol uses the secondary structure
              determination  given  in the PDB file if it exists.  Otherwise, it uses the DSSP algorithm as used
              by the RasMol structure command.

       Sidechain Set
              This set contains the functional sidechains of any amino acids and the base  of  each  nucleotide.
              These  are  the  atoms  not  part  of  the  polypeptide  N-C-C-O backbone of proteins or the sugar
              phosphate backbone of nucleic acids.  Use the  RasMol  predefined  sets  protein  and  nucleic  to
              distinguish  between  the  two forms of sidechain.  Atoms in nucleic acids and proteins are either
              backbone or sidechain.  This set is equivalent to the RasMol expression (protein or  nucleic)  and
              not backbone.

       Small Set
              All  amino  acids  are classified as either small, medium or large.  This set is equivalent to the
              RasMol atom expression amino and not (medium or large).

       Solvent Set
              This set contains the solvent atoms in the molecule coordinate file.  These are the  heterogeneous
              water  molecules, phosphate and sulphate ions. All hetero atoms are classified as either ligand or
              solvent atoms. All solvent atoms are classified as either water or ions.  This set  is  equivalent
              to the RasMol atom expressions hetero and not ligand and water or ions.

       Surface Set
              This  set  contains  the  atoms  in  those  amino acids that tend (prefer) to be on the surface of
              proteins, in contact with solvent molecules. This set refers to the amino acids preference and not
              the  actual  solvent  accessibility  for  the  current protein.  All amino acids are classified as
              either surface or buried.  This set is equivalent to the RasMol  atom  expression  amino  and  not
              buried.

       Turn Set
              This set contains all atoms that form part of a protein turns as determined by either the PDB file
              author or Kabsch and Sander's DSSP algorithm. By default,  RasMol  uses  the  secondary  structure
              determination  given  in the PDB file if it exists.  Otherwise, it uses the DSSP algorithm as used
              by the RasMol structure command.

       Water Set
              This set contains all the heterogeneous water molecules in the current database. A large number of
              water molecules are sometimes associated with protein and nucleic acid structures determined by X-
              ray crystallography. These atoms tend to clutter an image.  All hetero  atoms  are  classified  as
              either ligand or solvent atoms. The solvent atoms are further classified as either water or ions.

       Set Summary
              The table below summarises RasMol's classification of the common amino acids.

COLOUR SCHEMES

       The RasMol colour command allows different objects (such as atoms, bonds and ribbon segments) to be given
       a specified colour. Typically this colour is either a RasMol predefined colour name  or  an  RGB  triple.
       Additionally  RasMol  also  supports  alt,  amino,  chain, charge, cpk, group, model, shapely, structure,
       temperature or user colour schemes for atoms, and  hbond  type  colour  scheme  for  hydrogen  bonds  and
       electrostatic  potential  colour  scheme  for dot surfaces.  The 24 currently predefined colour names are
       Black, Blue, BlueTint, Brown, Cyan, Gold, Grey, Green, GreenBlue, GreenTint,  HotPink,  Magenta,  Orange,
       Pink, PinkTint, Purple, Red, RedOrange, SeaGreen, SkyBlue, Violet, White, Yellow and YellowTint

       If  you  frequently wish to use a colour not predefined, you can write a one-line script. For example, if
       you make the file grey.col containing the line, colour  [180,180,180]  #grey,  then  the  command  script
       grey.col colours the currently selected atom set grey.

       Alt Colours
              The  RasMol  alt  (Alternate Conformer) colour scheme codes the base structure with one colour and
              applies a limited number of colours to each alternate conformer.  In  a  RasMol  built  for  8-bit
              colour  systems,  4  colours  are  allowed  for  alternate  conformers.  Otherwise,  8 colours are
              available.

       Amino Colours
              The RasMol amino colour scheme colours amino acids according to traditional amino acid properties.
              The  purpose  of colouring is to identify amino acids in an unusual or surprising environment. The
              outer parts of a protein that are polar  are  visible  (bright)  colours  and  non-polar  residues
              darker.  Most  colours  are  hallowed  by  tradition. This colour scheme is similar to the shapely
              scheme.

       Chain Colours
              The RasMol chain colour scheme assigns each macromolecular chain  a  unique  colour.  This  colour
              scheme  is  particularly  useful  for  distinguishing  the  parts  of  multimeric structure or the
              individual 'strands' of a DNA chain.  Chain can be selected from the RasMol Colours menu.

       Charge Colours
              The RasMol charge colour scheme colour codes each atom according to the charge value stored in the
              input  file  (or  beta factor field of PDB files). High values are coloured in blue (positive) and
              lower values coloured in red (negative). Rather than use a fixed scale this scheme determines  the
              maximum  and  minimum  values  of  the  charge/temperature field and interpolates from red to blue
              appropriately. Hence, green cannot be assumed to be 'no net charge' charge.

              The difference between the charge and temperature colour schemes is  that  increasing  temperature
              values proceed from blue to red, whereas increasing charge values go from red to blue.

              If  the  charge/temperature field stores reasonable values it is possible to use the RasMol colour
              dots potential command  to  colour  code  a  dot  surface  (generated  by  the  dots  command)  by
              electrostatic potential.

       CPK Colours
              The  RasMol cpk colour scheme is based upon the colours of the popular plastic spacefilling models
              which were developed by Corey, Pauling and later improved by Kultun. This  colour  scheme  colours
              'atom'  objects  by  the  atom (element) type. This is the scheme conventionally used by chemists.
              The assignment of the most commonly used element types to colours is given below.

       Group Colours
              The RasMol group colour scheme colour codes residues by their position in a macromolecular  chain.
              Each  chain is drawn as a smooth spectrum from blue through green, yellow and orange to red. Hence
              the N terminus of proteins and 5' terminus of nucleic acids are coloured red and the C terminus of
              proteins  and  3'  terminus  of  nucleic acids are drawn in blue. If a chain has a large number of
              heterogeneous molecules associated with it, the macromolecule may not be drawn in the full 'range'
              of the spectrum.  Group can be selected from the RasMol Colours menu.

              If a chain has a large number of heterogeneous molecules associated with it, the macromolecule may
              not be drawn in the full range of the spectrum. When RasMol performs group  colouring  it  decides
              the  range  of  colours it uses from the residue numbering given in the PDB file. Hence the lowest
              residue number is displayed  in  blue  and  the  highest  residue  number  is  displayed  as  red.
              Unfortunately, if a PDB file contains a large number of heteroatoms, such as water molecules, that
              occupy the high residue numbers, the protein is displayed in the blue-green end  of  the  spectrum
              and  the waters in the yellow-red end of the spectrum. This is aggravated by there typically being
              many more water molecules than amino acid residues. The solution to this problem  is  to  use  the
              command  set  hetero  off  before  applying  the group colour scheme. This can also be achieved by
              toggling Hetero Atoms on the Options menu before selecting Group on the Colour menu. This  command
              instructs RasMol to only use non-hetero residues in the group colour scaling.

       NMR Model Colours
              The  RasMol model colour scheme codes each NMR model with a distinct colour.  The NMR model number
              is taken as a numeric value.  High values are coloured in blue and lower values coloured  in  red.
              Rather than use a fixed scale this scheme determines the maximum value of the NMR model number and
              interpolates from red to blue appropriately.

       Shapely Colours
              The RasMol shapely colour scheme colour codes residues by amino  acid  property.  This  scheme  is
              based  upon Bob Fletterick's "Shapely Models". Each amino acid and nucleic acid residue is given a
              unique colour. The shapely colour scheme is used by David Bacon's Raster3D  program.  This  colour
              scheme is similar to the amino colour scheme.

       Structure Colours
              The  RasMol  structure  colour  scheme colours the molecule by protein secondary structure.  Alpha
              helices are coloured magenta, [240,0,128], beta sheets are coloured yellow, [255,255,0], turns are
              coloured  pale  blue,  [96,128,255]  and  all  other  residues  are  coloured white. The secondary
              structure is either read from the PDB file (HELIX, SHEET  and  TURN  records),  if  available,  or
              determined  using  Kabsch and Sander's DSSP algorithm. The RasMol structure command may be used to
              force DSSP's structure assignment to be used.

       Temperature Colours
              The RasMol temperature  colour  scheme  colour  codes  each  atom  according  to  the  anisotropic
              temperature  (beta)  value  stored  in  the  PDB  file.  Typically  this  gives  a  measure of the
              mobility/uncertainty of a given atom's position. High values are coloured in warmer (red)  colours
              and lower values in colder (blue) colours. This feature is often used to associate a "scale" value
              [such as amino acid variability in viral mutants] with each atom in a PDB  file,  and  colour  the
              molecule appropriately.

              The  difference  between  the temperature and charge colour schemes is that increasing temperature
              values proceed from blue to red, whereas increasing charge values go from red to blue.

       User Colours
              The RasMol user colour scheme allows RasMol to use the colour scheme stored in the PDB  file.  The
              colours  for each atom are stored in COLO records placed in the PDB data file. This convention was
              introduced by David Bacon's Raster3D program.

       HBond Type Colours
              The RasMol type colour scheme applies only to hydrogen bonds, hence is used in the command  colour
              hbonds  type.   This  scheme  colour  codes  each  hydrogen bond according to the distance along a
              protein chain between hydrogen  bond  donor  and  acceptor.   This  schematic  representation  was
              introduced  by  Belhadj-Mostefa  and  Milner-White.  This representation gives a good insight into
              protein secondary structure (hbonds forming alpha helices appear red, those forming sheets  appear
              yellow and those forming turns appear magenta).

       Potential Colours
              The  RasMol  potential  colour  scheme  applies only to dot surfaces, hence is used in the command
              colour dots potential.  This scheme colours each currently  displayed  dot  by  the  electrostatic
              potential  at  that  point  in  space. This potential is calculated using Coulomb's law taking the
              temperature/charge field of the input file to be the charge assocated with that atom. This is  the
              same  interpretation  used  by the colour charge command. Like the charge colour scheme low values
              are blue/white and high values are red.

       Amino Acid Codes
              The following table lists the names, single letter and three letter codes of  each  of  the  amino
              acids.

       Booleans
              A  boolean  parameter  is  a  truth  value. Valid boolean values are 'true' and 'false', and their
              synonyms 'on' and 'off'. Boolean parameters are commonly  used  by  RasMol  to  either  enable  or
              disable a representation or option.

FILE FORMATS

       Protein Data Bank Files

       If  you  do  not  have  the  PDB documentation, you may find the following summary of the PDB file format
       useful. The Protein Data Bank is a computer-based archival database for macromolecular  structures.   The
       database  was  established in 1971 by Brookhaven National Laboratory, Upton, New York, as a public domain
       repository for resolved crystallographic structures. The Bank uses  a  uniform  format  to  store  atomic
       coordinates  and  partial  bond  connectivities  as  derived  from crystallographic studies.  In 1999 the
       Protein Data Bank moved to the Research Collaboratory for Structural Biology.

       PDB file entries consist of records of 80 characters each. Using the punched card analogy, columns 1 to 6
       contain  a  record-type  identifier, the columns 7 to 70 contain data. In older entries, columns 71 to 80
       are normally blank, but may contain sequence information added by library management  programs.   In  new
       entries  conforming  to  the 1996 PDB format, there is other information in those columns. The first four
       characters of the record identifier are sufficient to identify the  type  of  record  uniquely,  and  the
       syntax  of  each  record  is  independent  of  the  order  of  records  within any entry for a particular
       macromolecule.

       The only record types that are of major interest to the RasMol program are the ATOM  and  HETATM  records
       which  describe  the  position  of each atom. ATOM/HETATM records contain standard atom names and residue
       abbreviations, along with sequence identifiers, coordinates in Angstrom units,  occupancies  and  thermal
       motion  factors.  The  exact  details  are  given  below as a FORTRAN format statement.  The "fmt" column
       indicates use of the field in all PDB formats, in the 1992 and earlier formats or in the 1996  and  later
       formats.

       Residues  occur  in  order  starting from the N-terminal residue for proteins and 5'-terminus for nucleic
       acids. If the residue sequence is known, certain atom serial numbers may be omitted to allow  for  future
       insertion  of  any  missing  atoms. Within each residue, atoms are ordered in a standard manner, starting
       with the backbone (N-C-C-O for proteins) and proceeding in increasing remoteness from the  alpha  carbon,
       along the side chain.

       HETATM records are used to define post-translational modifications and cofactors associated with the main
       molecule. TER records are interpreted as breaks in the main molecule's backbone.

       If present, RasMol also inspects HEADER, COMPND,  HELIX,  SHEET,  TURN,  CONECT,  CRYST1,  SCALE,  MODEL,
       ENDMDL,  EXPDTA  and  END  records.  Information  such  as  the  name,  database  code, revision date and
       classification of the molecule are extracted from HEADER and COMPND records, initial secondary  structure
       assignments  are taken from HELIX, SHEET and TURN records, and the end of the file may be indicated by an
       END record.

       RasMol Interpretation of PDB fields
              Atoms located at 9999.000, 9999.000, 9999.000 are assumed to  be  Insight  pseudo  atoms  and  are
              ignored  by  RasMol.  Atom  names  beginning  ' Q' are also assumed to be pseudo atoms or position
              markers.

              When a data file contains an NMR structure, multiple conformations may be placed in a  single  PDB
              file  delimited by pairs of MODEL and ENDMDL records. RasMol displays all the NMR models contained
              in the file.

              Residue names "CSH", "CYH" and "CSM" are considered pseudonyms for cysteine "CYS".  Residue  names
              "WAT", "H20", "SOL" and "TIP" are considered pseudonyms for water "HOH". The residue name "D20" is
              consider heavy water "DOD". The residue name "SUL" is considered a sulphate ion "SO4". The residue
              name  "CPR"  is considered to be cis-proline and is translated as "PRO". The residue name "TRY" is
              considered a pseudonym for tryptophan "TRP".

              RasMol uses the HETATM fields to define the sets hetero, water, solvent and ligand. Any group with
              the name "HOH", "DOD", "SO4" or "PO4" (or aliased to one of these names by the preceding rules) is
              considered a solvent and is considered to be defined by a HETATM field.

              RasMol only respects CONECT connectivity records in PDB files containing  fewer  than  256  atoms.
              This  is  explained  in  more  detail  in the section on determining molecule connectivity. CONECT
              records that define a bond more than once are interpreted as specifying the  bond  order  of  that
              bond, i.e. a bond specified twice is a double bond and a bond specified three (or more) times is a
              triple bond.  This is not a standard PDB feature.

       PDB Colour Scheme Specification
              RasMol also accepts the supplementary COLO record type in the PDB files. This  record  format  was
              introduced  by  David  Bacon's  Raster3D  program for specifying the colour scheme to be used when
              rendering the molecule. This extension is not currently supported by the PDB. The COLO record  has
              the same basic record type as the ATOM and HETATM records described above.

              Colours  are  assigned  to  atoms using a matching process. The Mask field is used in the matching
              process as follows. First RasMol reads in and remembers all the ATOM, HETATM and COLO  records  in
              input  order.  When  the user-defined ('User') colour scheme is selected, RasMol goes through each
              remembered ATOM/HETATM record in turn, and searches for a COLO  record  that  matches  in  all  of
              columns  7  through 30. The first such COLO record to be found determines the colour and radius of
              the atom.

              Note that the Red, Green and Blue components are in  the  same  positions  as  the  X,  Y,  and  Z
              components  of  an  ATOM  or  HETA  record,  and the van der Waals radius goes in the place of the
              Occupancy. The Red, Green and Blue components must all be in the range 0 to 1.

              In order that one COLO record can provide colour and radius specifications for more than one  atom
              (e.g.  based on residue, atom type, or any other criterion for which labels can be given somewhere
              in columns 7 through 30), a 'don't-care' character, the hash mark "#" (number or  sharp  sign)  is
              used.  This  character,  when  found  in a COLO record, matches any character in the corresponding
              column in a ATOM/HETATM record. All other characters must match identically to count as  a  match.
              As  an  extension to the specification, any atom that fails to match a COLO record is displayed in
              white.

       Multiple NMR Models
              RasMol loads all of the NMR models from a PDB file no matter  which  command  is  used:  load  pdb
              <filename> or load nmrpdb <filename>

              Once  multiple NMR conformations have been loaded they may be manipulated with the atom expression
              extensions described in Primitive Expressions.  In  particular,  the  command  restrict  */1  will
              restrict the display to the first model only.

       CIF and mmCIF Format Files
              CIF  is  the  IUCr  standard  for  presentation  of  small  molecules and mmCIF is intended as the
              replacement for the fixed-field PDB format for presentation of macromolecular  structures.  RasMol
              can accept data sets in either format.

              There  are many useful sites on the World Wide Web where information tools and software related to
              CIF, mmCIF and the PDB can be found. The following are good starting points for exploration:

              The International Union of Crystallography  (IUCr)  provides  access  to  software,  dictionaries,
              policy  statements  and  documentation  relating  to  CIF  and  mmCIF  at:  IUCr, Chester, England
              (www.iucr.org/iucr-top/cif/) with many mirror sites.

              The Nucleic Acid Database Project provides access to its entries, software and documentation, with
              an  mmCIF page giving access to the dictionary and mmCIF software tools at Rutgers University, New
              Jersey, USA (http://ndbserver.rutgers.edu/NDB/mmcif) with many mirror sites.

              This version of RasMol restricts CIF or mmCIF tag values to essentially the  same  conventions  as
              are  used  for  the  fixed-field  PDB  format.  Thus  chain identifiers and alternate conformation
              identifiers are limited to a single character, atom names are limited to 4 characters, etc. RasMol
              interprets the following CIF and mmCIF tags: A search is made through multiple data blocks for the
              desired tags, so a single dataset may be composed from multiple data  blocks,  but  multiple  data
              sets may not be stacked in the same file.

MACHINE-SPECIFIC SUPPORT

       In  the  following  sections,  support  for  Monochrome  X-Windows,  Tcl/Tk  IPC, UNIX sockets based IPC,
       Compiling RasWin with Borland and MetroWerks are described.

       Monochrome X-Windows Support
              RasMol supports the many monochrome UNIX workstations typically found in academia, such as low-end
              SUN  workstations and NCD X-terminals. The X11 version of RasMol (when compiled in 8 bit mode) now
              detects black and white X-Windows displays and enables dithering automatically. The  use  of  run-
              time  error  diffusion  dithering  means  that  all  display modes of RasMol are available when in
              monochrome mode. For best results, users should experiment with the set ambient command to  ensure
              the maximum contrast in resulting images.

       Tcl/Tk IPC support
              Version 4 of Tk graphics library changed the protocol used to communicate between Tk applications.
              RasMol version 2.6 was modified such that it could communicate with both this new protocol and the
              previous  version  3  protocol supported by RasMol v2.5. Although Tcl/Tk 3.x applications may only
              communicate with other 3.x applications and Tcl/Tk 4.x applications with other  4.x  applications,
              these  changes  allow  RasMol  to  communicate  between processes with both protocols (potentially
              concurrently).

       UNIX sockets based IPC
              The UNIX implementation of RasMol supports BSD-style socket  communication.  An  identical  socket
              mechanism  is  also  being  developed for VMS, Apple Macintosh and Microsoft Windows systems. This
              should allow RasMol to interactively display results of  a  computation  on  a  remote  host.  The
              current  protocol  acts  as a TCP/IP server on port 21069 that executes command lines until either
              the command exit or the command quit is typed. The  command  exit  from  the  RasMol  server,  the
              command quit both disconnects the current session and terminates RasMol. This functionality may be
              tested using the UNIX command telnet <hostname> 21069.

       Compiling RasWin with Borland and MetroWerks
              A number of changes were made to the source code in the transition from  version  2.5  to  2.6  to
              allow  the  Microsoft Windows version of RasMol to compile using the Borland C/C++ compiler. These
              fixes include name changes for the standard library and special code to avoid a bug  in  _fmemset.
              Additional  changes  were  made  in  the  transition from 2.6 to 2.7 to allow compilation with the
              MetroWerks compilers.

BIBLIOGRAPHY

       Molecular Graphics

       [1] Nelson Max, "Computer Representation of Molecular Surfaces", IEEE Computer Graphics and Applications,
       pp.21-29, August 1983.

       [2] Arthur M. Lesk, "Protein Architecture: A Practical Approach", IRL Press Publishers, 1991.

       Molecular Graphics Programs

       [3]  Per  J.  Kraulis,  "MOLSCRIPT:  A  Program  to  Produce both Detailed and Schematic Plots of Protein
       Structures", Journal of Applied Crystallography, Vol.24, pp.946-950, 1991.

       [4] David Bacon and Wayne F. Anderson, "A Fast Algorithm for Rendering Space-Filling Molecule  Pictures",
       Journal of Molecular Graphics, Vol.6, No.4, pp.219-220, December 1988.

       [5]  David  C.  Richardson  and  Jane S. Richardson, "The Kinemage: A tool for Scientific Communication",
       Protein Science, Vol.1, No.1,pp.3-9, January 1992.

       [6] Mike Carson, "RIBBONS 2.0", Journal of Applied Crystallography, Vol.24, pp.958-961, 1991.

       [7] Conrad C. Huang, Eric F. Pettersen, Teri E. Klein, Thomas E.  Ferrin and Robert Langridge, "Conic:  A
       Fast  Renderer  for  Space-Filling  Molecules  with Shadows", Journal of Molecular Graphics, Vol.9, No.4,
       pp.230-236, December 1991.

       Molecular Biology Algorithms

       [8] Wolfgang Kabsch and Christian Sander, "Dictionary of Protein Secondary Structure: Pattern Recognition
       of Hydrogen-Bonded and Geometrical Features", Biopolymers, Vol.22, pp.2577-2637, 1983.

       [9]  Michael  L. Connolly, "Solvent-Accessible Surfaces of Proteins and Nucleic Acids", Science, Vol.221,
       No.4612, pp.709-713, August 1983.

       [10] Khaled Belhadj-Mostefa, Ron Poet and E. James Milner-White, "Displaying  Inter-Main  Chain  Hydrogen
       Bond Patterns in Proteins", Journal of Molecular Graphics, Vol.9, No.3, pp.194-197, September 1991.

       [11]  Mike  Carson,  "Ribbon  Models  of  Macromolecules",  Journal  of  Molecular Graphics, Vol.5, No.2,
       pp.103-106, June 1987.

       [12] Mike Carson and Charles E. Bugg, "Algorithm for Ribbon Models of  Proteins",  Journal  of  Molecular
       Graphics, Vol.4, No.2, pp.121-122, June 1986.

       [13]  H. Iijima, J. B. Dunbar Jr. and G. Marshall, "Calibration of Effective van der Waals Atomic Contact
       Radii for Proteins and Peptides", Proteins: Structure, Functions and Genetics, Vol.2, pp.330-339,1987.

       Graphics Algorithms

       [14] J. Foley, A. van Dam, S. Feiner and J. Hughes, "Computer Graphics:  Principles  and  Practice",  2nd
       Edition, Addison Wesley Publishers, 1990.

       [15]  J.  Cleary  and  G.  Wyvill,  "Analysis  of  an  Algorithm for Fast Ray Tracing using Uniform Space
       Subdivision", The Visual Computer, Vol.4, pp.65-83, 1988.

       [16] Thomas Porter,"Spherical Shading", Computer Graphics Vol.12, ACM SIGGRAPH, pp.282-285, 1978.

       [17] Jean-Michel Cense, "Exact Visibility Calculation for Space-Filling  Molecular  Models",  Journal  of
       Molecular Graphics, Vol.9, No.3, pp.191-193, September 1991.

       [18]  Chris Schafmeister, "Fast Algorithm for Generating CPK Images on Graphics Workstations", Journal of
       Molecular Graphics, Vol.8, No.4, pp.201-206, December 1990.

       [19] Bruce A. Johnson, "MSURF: A Rapid and General Program for the Representation of Molecular Surfaces",
       Journal of Molecular Graphics, Vol.5, No.3, pp.167-169, September 1987.

       File Formats

       [20]  Frances  C.  Bernstein  et  al.,  "The  Protein  Data  Bank:  A  Computer-Based  Archival  File for
       Macromolecular Structures", Journal of Molecular Biology, Vol.112, pp.535-542, 1977.

       [21] Arthur Dalby, James G. Nourse, W. Douglas Hounshell, Ann K. I.  Gushurst, David L. Grier, Burton  A.
       Leland and John Laufer, "Description of Several Chemical File Formats Used by Computer Programs Developed
       at Molecular Design Limited", Journal of  Chemical  Information  and  Computer  Sciences,  Vol.32,  No.3,
       pp.244-255, 1992.

       [22]  Adobe  Systems  Inc.,  "PostScript  Language Reference Manual", Addison-Wesley Publishers, Reading,
       Mass., 1985.

       [23] Philip E. Bourne et al., "The  Macromolecular  Crystallographic  Information  File  (mmCIF)",  Meth.
       Enzymol. (1997) 277, 571-590.

       [24] Sydney R. Hall, "The STAR File: a New Format for Electronic Data Transfer and Archiving", Journal of
       Chemical Information and Computer Sciences, Vol. 31, 326-333, 1991.

SEE ALSO

       The RasMol User Manual!

AUTHOR

       1992-1998 by Roger Sayle (rasmol@ggr.co.uk)

                                                    July 2009                                          RASMOL(1)